MEDICINAL DYNAMETER
AND
SCALE OF EQUIVALENTS.

Engraved for the Second American Edition of Paris’s Pharmacologia.

EXPLANATION.

This Instrument will shew on bare inspection, the quantity of active matter contained in any given weight or measure (according as it is solid or liquid) of any Officinal compound, and the dose of any preparation which will be equivalent in strength to any given quantity of any other of the same class. The active principles, or Medicinal Bases, are distinguished by capital letters, placed in coloured squares; and each Officinal Preparation is marked by a line corresponding in colour with that of its active ingredient. If we require the quantity of active matter in any given dose of an Officinal Preparation, we have only to bring such preparation to the number in question and the figure opposite the active ingredient answers the question, while those opposite to the other compounds of the same class denote the equivalent quantities. Unless otherwise expressed, the figures denote Grains for the solids, and Minim for the liquids.

Entered according to the Act of Congress, in the year One Thousand Eight Hundred and Thirty-one, by W. E. Dean, in the Clerk’s Office of the Southern District of New-York.

There is not an individual in the whole circle of the profession, to whom I could with greater satisfaction, or with so much propriety, dedicate this work, as to yourself.

Ardent and zealous in the advancement of our science, you must deeply deplore the prejudices that retard its progress;—eminently enlightened in Natural History, you can justly appreciate the importance of its applications to Medicine; while your well known earnestness in upholding the dignity, and in encouraging the legitimate exercise of our profession, marks you as the most proper patron of a work, the aim of which is to extinguish the false lights of empiricism, and to substitute a steady beacon on the solid and permanent basis of truth and science: at the same time, the extensive practice which your talents and urbanity so justly command in this metropolis, must long since have taught you the full extent of that empiricism which it has been my endeavour to expose, and the practical mischief of that ignorance which it has been my object to enlighten.

Nor let me omit to mention the claims of that friendship which has for many years subsisted between us; be assured that I am gratefully sensible of those personal obligations which so fully justify this public avowal of them; confidently trusting that you will not measure the gratitude which your kindness has inspired, by the merits of the offering by which it is acknowledged, but rather by the truth and sincerity of the Dedication, by which I am enabled to express

The Public are already in possession of many pharmaceutical compendiums and epitomes of plausible pretensions, composed with the view of directing the practice of the junior, and of relieving the occasional embarrassments of the more experienced practitioner. Nothing is farther from my intention than to disparage their several merits, or to question their claims to professional utility; but in truth and justice it must be confessed that, as far as these works relate to the art of composing scientific prescriptions, their authors have not escaped the too common error of supposing that the reader is already grounded in the first principles of the science; or, to borrow the figurative illustration of a popular writer, that while they are in the ship of science, they forget the disciple cannot arrive without a boat. I am not acquainted with any book that is calculated to furnish such assistance, or which professes to teach the Grammar, and ground-work of this important branch of medical knowledge. Numerous are the works which present us with the detail, but no one with the philosophy of the subject. We have copious catalogues of formal recipes, and many of unexceptionable propriety, but the compilers do not venture to discuss the principles upon which they were constructed, nor do they explain the part which each ingredient is supposed to perform in the general scheme of the formula; they cannot therefore lead to any useful generalization, and the young practitioner, without a beacon that can direct his course in safety, is abandoned to the alternative of two great evils—a feeble and servile routine, on one hand, or a wild and lawless empiricism, on the other. The present volume is an attempt to supply this deficiency: and while I am anxious to ‘catch the ideas which lead from ignorance to knowledge,’ it is not without hope that I may also be able to suggest the means by which our already acquired knowledge may be more widely and usefully extended; and, by offering a collective and arranged view of the objects and resources of medicinal combination, to establish its practice upon the basis of science, and thereby to render its future career of improvement progressive with that of the other branches of medicine; or, to follow up the figurative illustration already introduced, to furnish a boat, which may not only convey the disciple to the ship, but which may also assist in piloting the ship herself from her shallow and treacherous moorings. That the design however of the present work may not be mistaken, it is essential to remark that it is elementary only in reference to the art of prescribing, for it is presumed that the student is already acquainted with the common manipulations of pharmacy, and with the first principles of chemistry. When any allusions are made to the processes of the Pharmacopœia, they are to be viiiunderstood as being only supplementary, or as explanatory of their nature, in reference to the application or medicinal powers of the substance in question. The term Pharmacologia, as applied to the present work, may therefore be considered as contradistinctive to that of Pharmacopœia; for while the latter denotes the processes for preparing, the former comprehends the scientific methods of administering medicinal bodies, and explains the objects and theory of their operation. The articles of the Materia Medica have been arranged in alphabetical order, not only as being that best calculated for reference, but one which, in an elementary work at least, is less likely to mislead, than any arrangement founded on their medicinal powers; for in consequence of the difficulty of discriminating in every case between the primary and secondary effects of a medicine, substances very dissimilar in their nature, have been enlisted into the same artificial group, and when several of such bodies have, from a reliance upon their unity of action, been associated together in a medicinal mixture, it has often happened that, like the armed men of Cadmus, they have opposed and destroyed each other. The object and application of the black marginal letters, to which the name of Key Letters has been given, are fully explained in the First Part of the work, and it is hoped, that the scheme possesses a more substantial claim to notice than that of mere novelty: it will be perceived that in the enumeration of the officinal formulæ these letters are also occasionally introduced, to express the manner in which the particular substance, under the head of which it stands, operates in the combination. If any apology be necessary for the introduction of the medicinal formulæ, it may be offered in the words of Quintillian, who very justly observes, “In omnibus fere minus valent præcepta quam exempla;” or in the language of Seneca; “Longum est iter per præcepta, breve et efficax per exempla.” Under the history of each article, I have endeavoured to concentrate all that is required to be known for its efficacious administration, such as, 1. Its sensible qualities. 2. Its chemical composition, or the constituents in which its medicinal activity resides. 3. Its relative solubility in different menstrua, and the proportions in which it should be mixed, or combined with different bodies, in order to produce suspension, or saturation. 4. The Incompatible Substances; that is to say, those substances which are capable of destroying its properties, or of rendering its flavour or aspect unpleasant or disgusting. 5. The most eligible forms in which it can be exhibited. 6. Its specific doses. 7. Its Medicinal Uses, and Effects. 8. Its Preparations, Officinal as well as Extemporaneous. 9. Its Adulterations. That such information is indispensible for the elegant and successful exhibition of a remedy, must be sufficiently apparent; the injurious changes and modifications which substances undergo when they are improperly combined by the ignorant practitioner, are not as some have supposed imaginary, the mere deliramenta doctrinæ, or the whimsical suggestions of theoretical refinement, but they are really such as to render their powers unavailing, or to impart a dangerous violence to their operation. “Unda dabit flammas et dabit ignis aquas.”

In the history of the different medicinal preparations, the pharmacopœia of the London College is the standard to which I have always referred, although it will be perceived that I have frequently availed myself of the resources with which the pharmacopœias of Edinburgh and Dublin abound. To a knowledge of the numerous adulterations to which each article is so shamefully exposed, too much importance can be ixscarcely attached; and under this palpable source of medicinal fallacy and failure, may be fairly included those secret and illegitimate deviations from the acknowledged modes of preparation, as laid down in the pharmacopœia, whether practised as expedients to obtain a lucrative notoriety, or from a conceit of their being improvements upon the ordinary processes; for instance, we have lately heard of a wholesale chemist who professes to supply a syrup of roses of very superior beauty, and who, for this purpose, substitutes the petals of the red (rosa gallica) for those of the damask rose (rosa centifolia); we need not be told, that a preparation of a more exquisite colour may be thus afforded, but allow me to ask if this underhanded substitution be not a manifest act of injustice to the medical practitioner, who, instead of a laxative syrup, receives one which is marked by the opposite character of astringency. These observations will not apply, of course, to those articles which are avowedly prepared by a new process; for in that case the practitioner is enabled to make his election, and either to adopt or refuse them at his discretion. Thus has Mr. Barry applied his ingenious patent apparatus for boiling in vacuo, to the purpose of making Extracts; we might almost say a priori, that the results must be more active than those obtained in the ordinary way, but they must pass the ordeal of experience before they can be admitted into practice. As a brief notice of the most notorious Quack Medicines may be acceptable, the formulæ for their preparation have been appended in notes, each being placed at the foot of the particular article which constitutes its prominent ingredient; indeed it is essential that the practitioner should be acquainted with their composition, for although he would refuse to superintend the operation of a boasted panacea, it is but too probable that he may be called upon to counteract its baleful influence.

The Historical Introduction, comprehending the substance of the lectures delivered before the Royal College of Physicians of London, from the recently established chair of Materia Medica, has been prefixed to the work, at the desire of several of the auditors; and I confess my readiness to comply with this request, as it enabled me at once to obviate any misconception or unjust representation of those remarks which I felt it my bounden duty to offer to the College.

It will be observed that the work itself is divided into two separate and very distinct parts, the First comprehending the principles of the art of combination,—the Second, the medicinal history, and chemical habitudes of the bodies which are the subjects of such combination. These comprise every legitimate source of instruction, and to the young and industrious student, they are at once the Loom and the Raw Material. Let him therefore abandon those flimsy and ill-adapted textures, that are kept ready fabricated for the service of ignorance and indolence, and by actuating the machinery himself, weave the materials with which he is here presented into the forms and objects that may best fulfil his intentions, and meet the various exigencies of each particular occasion.

“It has been very justly observed that there is a certain maturity of the human mind acquired from generation to generation, in the MASS, as there is in the different stages of life in the INDIVIDUAL man;—What is history when thus philosophically studied, but the faithful record of this progress? pointing out for our instruction the various causes which have retarded or accelerated it in different ages and countries.”

AN ANALYTICAL INQUIRY INTO THE MORE REMARKABLE CAUSES WHICH HAVE, IN DIFFERENT AGES AND COUNTRIES, OPERATED IN PRODUCING THE REVOLUTIONS THAT CHARACTERISE THE HISTORY OF MEDICINAL SUBSTANCES.

Before I proceed to discuss the particular views which I am prepared to submit to the College, on the important but obscure subject of medicinal combination, I propose to take a sweeping and rapid sketch of the different moral and physical causes which have operated in producing the extraordinary vicissitudes, so eminently characteristic of the history of Materia Medica. Such an introduction is naturally suggested by the first glance at the extensive and motly assemblage of substances with which our cabinets^[1] are overwhelmed. It is impossible to cast our eyes over such multiplied groups, without being forcibly struck with the palpable absurdity of some—the total want of activity in many—and the uncertain and precarious reputation of all—or, without feeling an eager curiosity to enquire, from the combination of what causes it can have happened, that substances, at one period in the highest esteem, and of generally acknowledged utility, have fallen into total neglect and disrepute;—why others, of humble pretensions and little significance, have maintained their ground for so many centuries; and on what account, materials of no energy whatever, have received the indisputable sanction and unqualified support of the best and wisest practitioners of the age. That such fluctuations in opinion and versatility in practice should have produced, even in the most candid and learned observers, an unfavourable impression with regard to the general efficacy of medicines, can hardly excite our astonishment, much less our indignation; nor can we be surprised to find, that another portion of mankind has at once arraigned Physic as a fallacious 4art, or derided it as a composition of error and fraud.^[2] They ask—and it must be confessed that they ask with reason—what pledge can be afforded them, that the boasted remedies of the present day will not, like their predecessors, fall into disrepute, and in their turn serve only as humiliating memorials of the credulity and infatuation of the physicians who commended and prescribed them? There is surely no question connected with our subject which can be more interesting and important, no one which requires a more cool and dispassionate inquiry, and certainly not any which can be more appropriate for a lecture, introductory to the history of Materia Medica. I shall therefore proceed to examine with some attention the revolutions which have thus taken place in the opinions and belief of mankind, with regard to the efficacy and powers of different medicinal agents; such an inquiry, by referring them to causes capable of a philosophical investigation, is calculated to remove many of the unjust prejudices which have been excited, to quiet the doubts and alarms which have been so industriously propagated, and, at the same time, to obviate the recurrence of several sources of error and disappointment.

This moral view of events, without any regard to chronological minutiæ, may be denominated the Philosophy of History, and should be carefully distinguished from that technical and barren erudition, which consists in a mere knowledge of names and dates, and which is perused by the medical student with as much apathy, and as little profit, as the monk counts his bead-roll. It has been very justly observed, that there is a certain maturity of the human mind, acquired from generation to generation, in the mass, as there is in the different stages of life, in the individual man; what is history, when thus philosophically studied, but the faithful record of this progress? pointing out for our instruction the various causes which have retarded or accelerated it in different ages and countries.

In tracing the history of the Materia Medica to its earliest periods, we shall find that its progress towards its present advanced state, has been very slow and unequal, very unlike the steady and successive improvement which has attended other branches of natural knowledge; we shall perceive even that its advancement has been continually arrested, and often entirely subverted, by the caprices, prejudices, superstitions, and knavery of mankind; unlike too the other branches of science, it is incapable of successful generalization; in the progress of the history of remedies, when are we able to produce a discovery or improvement, which has been the result of that happy combination of Observation, Analogy, and Experiment,^[3] which has so eminently rewarded the labours of modern science? Thus, Observation led Newton to discover that the refractive power of transparent substances was, in general, in the ratio of their density, but 5that, of substances of equal density, those which possessed the refractive power in a higher degree were inflammable.^[4] Analogy induced him to conclude that, on this account, water must contain an inflammable principle, and Experiment enabled Cavendish and Lavoisier to demonstrate the surprising truth of Newton’s induction, in their immortal discovery of the chemical composition of that fluid.

The history of Astronomy furnishes another illustration equally beautiful and instructive,—The Astronomer observed certain oscillations in the motions of Saturn and Jupiter; by Analogy he conjectured that this phenomenon was produced by the influence of a planet still more remote: a supposition which was happily confirmed by a telescopic experiment, in the discovery of Uranus, by Herschel.

But it is clear that such principles of research, and combination of methods, can rarely be applied in the investigation of remedies, for every problem which involves the phenomena of life is unavoidably embarrassed by circumstances, so complicated in their nature, and fluctuating in their operation, as to set at defiance every attempt to appreciate their influence; thus an observation or experiment upon the effects of a medicine is liable to a thousand fallacies, unless it be carefully repeated under the various circumstances of health and disease, in different climates, and on different constitutions. We all know how very differently opium, or mercury, will act upon different individuals, or even upon the same individual, at different times, or under different circumstances; the effect of a stimulant upon the living body is not in the ratio of the intensity of its impulse, but in proportion to the degree of excitement, or vital susceptibility of the individual, to whom it is applied. This is illustrated in a clear and familiar manner, by the very different sensations of heat which the same temperature will produce under different circumstances. In the road over the Andes, at about half way between the foot and the summit, there is a cottage in which the ascending and descending travellers meet; the former, who have just quitted the sultry vallies at the base, are so relaxed, that the sudden diminution of temperature produces in them the feeling of intense cold, whilst the latter, who have left the frozen summits of the mountain, are overcome by the distressing sensation of extreme heat.

But we need not climb the Andes for an illustration; if we plunge one hand into a basin of hot, and the other into one of cold water, and then mix the contents of each vessel, and replace both hands in the mixture, we shall experience the sensation of heat and cold, from one and the same medium; the hand, that had been previously in the hot, will feel cold, whilst that which had been immersed in the cold water, will experience a sensation of heat. Upon the same principle, ardent spirits will produce very opposite effects upon different constitutions and temperaments, and we are thus enabled to reconcile the conflicting testimonies respecting the powers of opium in the cure of fever: aliments, also, which under ordinary circumstances would occasion but little effect, may in certain conditions of the system, act as powerful stimulants; a fact which is well exemplified by the history of persons who have been enclosed in coal mines for several days without food, from the accidental falling in of the 6surrounding strata, when they have been as much intoxicated by a basin of broth, as a person, in common circumstances, would have been by two or more bottles of wine.^[5] Many instances will suggest themselves to the practitioner in farther illustration of these views, and I shall have occasion to recur to the subject at a future period.

To such causes we must attribute the barren labours of the ancient empirics, who saw without discerning, administered without discriminating, and concluded without reasoning; nor should we be surprised at the very imperfect state of the materia medica, as far as it depends upon what is commonly called experience, complicated as this subject is by its numberless relations with Physiology, Pathology, and Chemistry. John Ray attempted to enumerate the virtues of plants from experience, and the system serves only to commemorate his failure. Vogel likewise professed to assign to substances, those powers which had been learnt from accumulated experience; and he speaks of roasted toad^[6] as a specific for the pains of gout, and asserts that a person may secure himself for the whole year from angina by eating a roasted swallow! Such must ever be the case, when medicines derive their origin from false experience, and their reputation from blind credulity.

Analogy has undoubtedly been a powerful instrument in the improvement, extension, and correction of the materia medica, but it has been chiefly confined to modern times; for in the earlier ages, Chemistry had not so far unfolded the composition of bodies, as to furnish any just idea of their relations to each other, nor had the science of Botany taught us the value and importance of the natural affinities which exist in the vegetable kingdom.

With respect to the fallacies to which such analogies are exposed, I shall hereafter speak at some length, and examine the pretensions of those ultra chemists of the present day who have upon every occasion arraigned, at their self-constituted tribunal, the propriety of our medicinal combinations, and the validity of our national pharmacopœias.

In addition to the obstacles already enumerated, the progress of our knowledge respecting the virtues of medicines has met with others of a moral character, which have deprived us in a great degree of another obvious method of research, and rendered our dependance upon testimony uncertain, and often entirely fallacious. The human understanding, as Lord Bacon justly remarks, is not a mere faculty of apprehension, but is affected, more or less, by the will and the passions; what man wishes to be true, that he too easily believes to be so, and I conceive that physic has, of all the sciences, the least pretensions to proclaim itself independent of the empire of the passions.

In our researches to discover and fix the period when remedies were 7first applied for the alleviation of bodily suffering, we are soon lost in conjecture, or involved in fable; we are unable to reach the period in any country, when the inhabitants were destitute of medical resources, and we find among the most uncultivated tribes, that medicine is cherished as a blessing and practised as an art, as by the inhabitants of New Holland and New Zealand, by those of Lapland and Greenland, of North America, and of the interior of Africa. The personal feelings of the sufferer, and the anxiety of those about him, must, in the rudest state of society, have incited a spirit of industry and research to procure alleviation, the modification of heat and cold, of moisture and dryness, and the regulation and change of diet and habit, must have intuitively suggested themselves for the relief of pain;^[7] and when these resources failed, charms, amulets, and incantations,^[8] were the natural expedients of the barbarian, ever more inclined to indulge the delusive hope of superstition, than to listen to the voice of sober reason. Traces of amulets may be discovered in very early history. The learned Dr. Warburton is evidently mistaken, when he assigns the origin of these magical instruments to the age of the Ptolemies, which was not more than 300 years before Christ; this is at once refuted by the testimony of Galen, who tells us that the Egyptian king, Nechepsus, who lived 630 years before the Christian era, had written, that a green jasper cut into the form of a dragon surrounded with rays, if applied externally, would strengthen the stomach and organs of digestion.^[9] We have moreover the authority of the Scriptures in support of this opinion; for what were the ear-rings which Jacob buried under the oak of Sechem, as related in Genesis, but amulets? and we are informed by Josephus, in his Antiquities of the Jews,^[10] that Solomon discovered a plant efficacious in the cure of Epilepsy, and that he employed the aid of a charm or spell for the purpose of assisting its virtues; the root of the herb was concealed in a ring, which was applied to the nostrils of the Demoniac, and Josephus remarks that he himself saw a Jewish Priest practise the art of Solomon with complete success in the presence of Vespasian, his sons, and the tribunes of the Roman army.^[11] Nor were such means confined to dark and barbarous ages; Theophrastus pronounced Pericles to be insane, because he discovered that he wore an amulet about his neck; and, in the declining æra of the Roman empire, we find that this superstitious custom was so general, that the Emperor 8Caracalla was induced to make a public edict ordaining that no man should wear any superstitious amulets about his person.

In the progress of civilization, various fortuitous incidents,^[12] and even errors in the choice and preparation of aliments, must have gradually unfolded the remedial powers of many natural substances; these were recorded, and the authentic history of medicine may date its commencement from the period when such records began.

The Chaldeans and Babylonians, we are told by Herodotus, carried their sick to the public roads and markets, that travellers might converse with them, and communicate any remedies which had been successfully used in similar cases; this custom continued during many ages in Assyria; and Strabo states that it prevailed also amongst the ancient Lusitanians, or Portuguese: in this manner, however, the results of experience descended only by oral tradition; it was in the temple of Esculapius in Greece that medical information was first recorded; diseases and cures were there registered on durable tablets of marble; the priests^[13] and priestesses, who were the guardians of the temple, prepared the remedies and directed their application, and thus commenced the profession of Physic. With respect to the actual nature of these remedies, it is useless to inquire; the lapse of ages, loss of records, change of language, and ambiguity of description, have rendered every learned research unsatisfactory; indeed we are in doubt with regard to many of the medicines which even Hippocrates employed. It is however clearly shewn by the earliest records, that the ancients were in the possession of many powerful remedies; thus Melampus of Argos, the most ancient Greek physician with whom we are acquainted, is said to have cured one of the Argonauts of sterility, by administering the rust of iron in wine for ten days; and the same physician used hellebore as a purge, on the daughters of king Prætus, who were afflicted with melancholy. Venesection was also a remedy of very early origin; for Podalirius, on his return from the Trojan war, cured the daughter of Damethus, who had fallen from a height, by bleeding her in both arms. Opium, or a preparation of the poppy, was certainly known in the earliest ages; it was probably opium that Helen mixed with wine, and gave to the guests of Menelaus, under the expressive name of nepenthe,^[14] to drive away their cares, and increase their hilarity; and this conjecture receives much support from the fact, that the nepenthe of Homer was obtained from the Egyptian Thebes;^[15] 9and if we may credit the opinion of Dr. Darwin, the Cumæan Sibyll never sat on the portending tripod without first swallowing a few drops of the juice of the Cherry-laurel.^[16]

There is reason to believe that the Pagan priesthood were under the influence of some powerful narcotic during the display of their oracular powers, but the effects produced would seem to resemble rather those of Opium, or perhaps of Stramonium, than of the Prussic acid. Monardes tells us that the priests of the American Indians, whenever they were consulted by the chief gentlemen, or casiques as they are called, took certain leaves of the Tobacco, and cast them into the fire, and then received the smoke, which they thus produced, in their mouths, in consequence of which they fell down upon the ground; and that after having remained for some time in a stupor, they recovered, and delivered the answers which they pretended to have received, during their supposed intercourse with the world of spirits.

The sedative powers of the Lactuca Sativa, or Lettuce,^[17] were known also in the earliest times; among the fables of antiquity, we read that after the death of Adonis, Venus threw herself on a bed of lettuces, to lull her grief, and repress her desires. The sea onion or Squill, was administered in cases of dropsy by the Egyptians, under the mystic title of the Eye of Typhon. The practices of incision and scarification were employed in the camp of the Greeks before Troy, and the application of spirit to wounds was also understood, for we find the experienced Nestor applying a cataplasm, composed of cheese, onion, and meal, mixed up with the wine of Pramnos, to the wounds of Machaon.^[18]

The revolutions and vicissitudes which remedies have undergone, in medical as well as popular opinion, from the ignorance of some ages, the learning of others, the superstitions of the weak, and the designs of the crafty, afford ample subject for philosophical reflection; some of these revolutions I shall proceed to investigate, classing them under the prominent causes which have produced them, viz. Superstition—Credulity—Scepticism—False Theory—Devotion to Authority, and Established Routine—The assigning to Art that which was the effect of unassisted Nature—The assigning to peculiar substances Properties, deduced from Experiments made on inferior Animals—Ambiguity of Nomenclature—The progress of Botanical Science—The application, and misapplication of Chemical Philosophy—The Influence of Climate and Season on Diseases, as well as on the properties, and operations of their Remedies—The ignorant Preparation, or fraudulent Adulteration of Medicines—The 10unseasonable collection of those remedies which are of vegetable origin,—and, the obscurity which has attended the operation of compound medicines.

SUPERSTITION.

A belief in the interposition of supernatural powers in the direction of earthly events, has prevailed in every age and country, in an inverse ratio with its state of civilization, or in the exact proportion to its want of knowledge. “In the opinion of the ignorant multitude,” says Lord Bacon, “witches and impostors have always held a competition with physicians.” Galen also complains of this circumstance, and observes that his patients were more obedient to the oracle in the temple of Esculapius, or to their own dreams, than they were to his prescriptions. The same popular imbecility is evidently allegorized in the mythology of the ancient poets, when they made both Esculapius and Circe the children of Apollo; in truth, there is an unaccountable propensity in the human mind, unless subjected to a very long course of discipline, to indulge in the belief of what is improbable and supernatural; and this is perhaps more conspicuous with respect to physic than to any other affair of common life, both because the nature of diseases and the art of curing them are more obscure, and because disease necessarily awakens fear, and fear and ignorance are the natural parents of superstition; every disease therefore, the origin and cause of which did not immediately strike the senses, has in all ages been attributed by the ignorant to the wrath of heaven, to the resentment of some invisible demon, or to some malignant aspect of the stars;^[19] and hence the introduction of a rabble of superstitious remedies, not a few of which were rather intended as expiations at the shrines of these offended spirits, than as natural agents possessing medicinal powers. The introduction of precious stones into the materia medica, arose from an Arabian superstition of this kind; indeed De Boot, who has written extensively upon the subject, does not pretend to account for the virtues of gems, upon any philosophical principle, but from their being the residence of spirits, and he adds that such substances, from their beauty, splendour and value, are well adapted as receptacles for good spirits!^[20]

11Every substance whose origin is involved in mystery,^[21] has at different times been eagerly applied to the purposes of medicine: not long since, one of those showers which are now known to consist of the excrement of insects, fell in the north of Italy; the inhabitants regarded it as Manna, or some supernatural panacea, and they swallowed it with such avidity, that it was only by extreme address, that a small quantity was obtained for a chemical examination.

A propensity to attribute every ordinary and natural effect to some extraordinary and unnatural cause, is one of the striking peculiarities of medical superstition; it seeks also explanations from the most preposterous agents, when obvious and natural ones are in readiness to solve the problem. Soranus, for instance, who was cotemporary with Galen, and wrote the life of Hippocrates!^[22] tells us that honey proved an easy remedy for the aphthæ of children, but instead of at once referring the fact to the medical qualities of the honey, he very gravely explains it, from its having been taken from bees that hived near the tomb of Hippocrates! And even those salutary virtues which many herbs possess, were, in these times of superstitious delusion, attributed rather to the planet under whose ascendancy they were collected or prepared, than to any natural and intrinsic properties in the plants themselves; indeed such was the supposed importance of planetary influence,^[23] that it was usual to prefix to receipts a symbol of the planet under whose reign the ingredients were to be collected, and it is not perhaps generally known, that the character which we at this day place at the head of our prescriptions, and which is understood, and supposed to mean Recipe, is a relict of the astrological symbol of Jupiter, as may be seen in many of the older works on pharmacy, although it is at present so disguised by the addition of the down stroke, which converts it into the letter ℞, that were it not for its cloven foot, we might be led to question the fact of its superstitious origin.

12

A knowledge of this ancient and popular belief in Sideral influence, will enable us to explain many superstitions in Physic; the custom, for instance, of administering cathartic medicines at stated periods and seasons, originated in an impression of their being more active at particular stages of the moon, or at certain conjunctions of the planets: a remnant of this superstition still exists to a considerable extent in Germany; and the practice of bleeding at ‘spring and fall,’ so long observed in this country, owed its existence to a similar belief. It was in consequence of the same superstition, that the metals were first distinguished by the names and signs of the planets; and as the latter were supposed to hold dominion over time, so were astrologers led to believe that some, more than others, had an influence on certain days of the week; and, moreover, that they could impart to the corresponding metals considerable efficacy upon the particular days which were devoted to them;^[24] from the same belief, some bodies were only prepared on certain days in the year; the celebrated earth of Lemnos was, as Galen describes, periodically dug with great ceremony, and it continued for many ages to be highly esteemed for its virtues; even at this day, the pit in which the clay is found is annually opened, with solemn rites by the priests, on the sixth day of August, six hours after sun rising, when a quantity is taken out, washed, dried, and then sealed with the Grand Signior’s seal, and sent to Constantinople. Formerly it was death to open the pit, or to seal the earth, on any other day in the year. In the botanical history of the middle ages, as more especially developed in Macer’s Herbal, there was not a plant of medicinal use, that was not placed under the dominion of some planet, and must neither be gathered nor applied but with observances that savoured of the 13most absurd superstition, and which we find were preserved as late as the seventeenth century, by the astrological herbalists, Turner, Culpepper, and Lovel.

It is not the least extraordinary feature in the history of medical superstition, that it should so frequently involve in its trammels persons who, on every other occasion, would resent with indignation any attempt to talk them out of their reason, and still more so, to persuade them out of their senses; and yet we have continual proofs of its extensive influence over powerful and cultivated minds; in ancient times we may adduce the wise Cicero, and the no less philosophical Aurelius, while in modern days we need only recall to our recollection the number of persons of superior rank and intelligence, who were actually persuaded to submit to the magnetising operations of Miss Prescott, and some of them were even induced to believe that a beneficial influence had been produced by the spells of this modern Circe.

Lord Bacon, with all his philosophy, betrayed a disposition to believe in the virtue of charms and amulets; and Boyle^[25] seriously recommends the thigh bone of an executed criminal, as a powerful remedy in dysentery. Amongst the remedies of Sir Theodore Mayerne, known to commentators as the Doctor Caius of Shakspeare, who was physician to three English Sovereigns, and who, by his personal authority, put an end to the distinctions of chemical and galenical practitioners in England, we shall find the secundines of a woman in her first labour with a male child; the bowels of a mole, cut open alive; mummy made of the lungs of a man who had died a violent death; with a variety of remedies, equally absurd, and alike disgusting.

It merits notice, that the medicinal celebrity of a substance has not unfrequently survived the tradition of its superstitious origin, in the same manner that many of our popular customs and rites have continued, through a series of years, to exact a respectful observance, although the circumstances which gave origin to them have been obscured and lost in the gloom of unrecorded ages. Does not the fond parent still suspend the coral toy around the neck of her infant, without being in the least aware of the superstitious belief^[26] from which the custom originated? while the chorus of derry down is re-echoed by those who never heard of the Druids, much less of the choral hymns with which their groves resounded, at the time of their gathering the misletoe; and how many a medical practitioner continues to administer this sacred plant, (Viscus 14Quercinus) for the cure of his epileptic patients, without the least suspicion that it owes its reputation to the same mysterious source of superstition and imposture? Nor is this the only faint vestige of druidism which can be adduced. Mr. Lightfoot states, with much plausibility, that in the highlands of Scotland, evidence still exists in proof of the high esteem in which those ancient Magi held the Quicken tree, or Mountain Ash, (Sorbus Aucuparia) for it is more frequently than any other, found planted in the neighbourhood of druidical circles of stones; and it is a curious fact, that it should be still believed that a small part of this tree, carried about a person, is a charm against all bodily evils,—the dairy-maid drives the cattle with a switch of the Roan tree, for so it is called in the highlands; and in one part of Scotland, the sheep and lambs are, on the first of May, ever made to pass through a hoop of Roan wood.

It is also necessary to state, that many of the practices which superstition has at different times suggested, have not been alike absurd; nay, some of them have even possessed, by accident, natural powers of considerable efficacy, whilst others, although, ridiculous in themselves, have actually led to results and discoveries of great practical importance. The most remarkable instance of this kind upon record is that of the Sympathetic powder of Sir Kenelm Digby,^[27] Knight of Montpellier. Whenever any wound had been inflicted, this powder was applied to the weapon that had inflicted it, which was, moreover, covered with ointment, and dressed two or three times a-day.^[28] The wound itself in the mean time 15was directed to be brought together, and carefully bound up with clean linen rags, but, ABOVE ALL, TO BE LET ALONE for seven days; at the end of which period the bandages were removed, when the wound was generally found perfectly united. The triumph of the cure was decreed to the mysterious agency of the sympathetic powder which had been so assiduously applied to the weapon; whereas, it is hardly necessary to observe, that the promptness of the cure depended upon the total exclusion of air from the wound, and upon the sanative operations of nature not having received any disturbance from the officious interference of art; the result, beyond all doubt, furnished the first hint, which led surgeons to the improved practice of healing wounds by what is technically called the first intention.

The rust of the spear of Telephus, mentioned in Homer as a cure for the wounds which that weapon inflicted, was probably Verdegris, and led to the discovery of its use as a surgical application.

Soon after the introduction of Gunpowder, cold water was very generally employed throughout Italy, as a dressing to gun-shot wounds; not however from any theory connected with the influence of diminished temperature or of moisture, but from a belief in a supernatural agency imparted to it by certain mysterious and magical ceremonies, which were duly performed immediately previous to its application: the continuance of the practice, however, threw some light upon the surgical treatment of these wounds, and led to a more rational management of them.

The inoculation of the small-pox in India, Turkey, and Wales, observes Sir Gilbert Blane, was practised on a superstitious principle, long before it was introduced as a rational practice into this country. The superstition consisted in buying it—for the efficacy of the operation, in giving safety, was supposed to depend upon a piece of money being left by the person who took it for insertion. The members of the National Vaccine Establishment, during the period I had a seat at the board, received from Mr. Dubois, a Missionary in India, a very interesting account of the services, derived from superstitious influence, in propagating the practice of vaccination through that uncivilized part of the globe. It appears from this document, that the greatest obstacle which vaccination encountered was a belief that the natural small-pox was a dispensation of a mischievous deity among them, whom they called Mah-ry Umma, or rather, that this disease was an incarnation of the dire Goddess herself, into the person who was infected with it; the fear of irritating her, and of exposing themselves to her resentment, necessarily rendered the natives of the East decidedly averse to vaccination, until a superstitious impression, equally powerful with respect to the new practice, was happily effected; this was no other than a belief, that the Goddess Mah-ry Umma had spontaneously chosen this new and milder mode of manifesting herself to her votaries, and that she might be worshipped with equal respect under this new shape.

Hydromancy is another superstition which has incidentally led to the discovery of the medicinal virtues of many mineral waters; a belief in the divining nature of certain springs and fountains is, perhaps, the most ancient and universal of all superstitions. The Castalian fountain, and many others amongst the Grecians, were supposed to be of a prophetic nature; by dipping a fair mirror into a well, the Patræans of Greece received, as they imagined, some notice of ensuing sickness or health. At 16this very day, the sick and lame are attracted to various hallowed springs; and to this practice, which has been observed for so many ages and in such different countries, we are no doubt indebted for a knowledge of the sanative powers of many mineral waters. There can be no doubt, moreover, but that in many cases, by affording encouragement and confidence to a dejected patient, and serenity to his mind, whether by the aid of reason or the influence of superstition, much benefit may arise; for the salutary and curative efforts of nature, in such a state of mind, must be much more likely to succeed; equally evident is it, that the most powerful effects may be induced by the administration of remedies which, from their disgusting nature, are calculated to excite strong and painful sensations of the mind.^[29] Celsus mentions, with confidence, several medicines of this kind for the cure of Epilepsy, as the warm blood of a recently slain Gladiator, or a certain portion of human, or horse flesh! and we find that remedies of this description were actually exhibited, and with success, by Kaw Boerhaave, in the cure of Epileptics in the poor-house at Haerlem. The powerful influence of confidence in the cure and prevention of disease, was well understood by the sages of antiquity; the Romans, in times of pestilence, elected a dictator with great solemnity, for the sole purpose of driving a nail into the wall of the temple of Jupiter—the effect was generally instantaneous—and while they thus imagined that they propitiated an offended deity, they in truth did but diminish the susceptibility to disease, by appeasing their own fears. Nor are there wanting in modern times, striking examples of the progress of an epidemic disease having been suddenly arrested by some exhilarating impression made upon the mass of the population.

In the celebrated siege of Breda, in 1625, by Spinola, the garrison suffered extreme distress from the ravages of Scurvy, and the Prince of Orange being unable to relieve the place, sent in, by a confidential messenger, a preparation which was directed to be added to a very large quantity of water, and to be given as a specific for the epidemic; the remedy was administered, and the garrison recovered its health, when it was afterwards acknowledged, that the substance in question was no other than a little colouring matter.

Amongst the numerous instances which have been cited to shew the power of faith over disease, or of the mind over the body, the cures performed by Royal Touch^[30] have been generally selected; but it would appear, 17upon the authority of Wiseman, that the cures which were thus effected, were in reality produced by a very different cause; for he states, that part of the duty of the Royal Physicians and Serjeant Surgeons was to select such patients, afflicted with scrofula, as evinced a tendency towards recovery, and that they took especial care to choose those who approached the age of puberty; in short, those only were produced whom nature had shewn a disposition to cure; and as the touch of the king, like the sympathetic powder of Digby, secured the patient from the mischievous importunities of art, so were the efforts of nature left free and uncontrolled, and the cure of the disease was not retarded or opposed by the operation of adverse remedies. The wonderful cures of Valentine Greatracks, performed in 1666, which were witnessed by cotemporary prelates, members of parliament, and fellows of the royal society, amongst whom was the celebrated Mr. Boyle, would probably upon investigation admit of a similar explanation; it deserves, however, to be noticed, that in all records of extraordinary cures performed by mysterious agents, there is a great desire to conceal the remedies and other curative means, which were simultaneously administered with them; thus Oribasius commends in high terms a necklace of Pœony root, for the cure of Epilepsy; but we learn that he always took care to accompany its use with copious evacuations, although he assigns to them no share of credit in the cure. In later times we have a good specimen of this deception presented to us in a work on Scrofula, by Mr. Morley, written, as we are informed, for the sole purpose of restoring the much injured character and use of the Vervain; in which the author directs the root of this plant to be tied with a yard of whited satin ribband, around the neck, where it is to remain until the patient is cured; but mark,—during this interval he calls to his aid the most active medicines in the materia medica!

The advantages which I have stated to have occasionally arisen from superstitious influence, must be understood as being generally accidental; indeed, in the history of superstitious practices, we do not find that their application was exclusively commended in cases likely to be influenced by the powers of faith or of the imagination, but, on the contrary, that they were as frequently directed in affections that were entirely placed beyond the control of the mind. Homer tells us, for instance, that the bleeding of Ulysses was stopped by a charm:^[31] and Cato the censor has 18favoured us with an incantation for the reduction of a dislocated limb. In certain instances, however, we are certainly bound to admit that the pagan priesthood, with their characteristic cunning, were careful to perform their superstitious incantations, in such cases only as were likely to receive the sanative assistance of Nature, so that they might attribute the fortunate results of her efforts, to the potent influence of their own arts. The extraordinary success which is related to have attended various superstitious ceremonials will thus find a plausible explanation: the miraculous gift, attributed by Herodotus to the Priestesses of Helen, is one amongst many others of this kind that might be adduced; the Grecian historian relates, that when the heads of ugly infants were adjusted on the altar of this temple, the individuals so treated acquired comeliness, and even beauty, as they advanced in growth: but is not such a change the ordinary and unassisted result of natural developement? Those large and prominent outlines which impart an unpleasing physiognomy to the infant, when proportioned and matured by growth, will generally assume features of intelligence in the adult face.

I shall conclude these observations, by remarking that, in the history of religious ceremonials, we sometimes discover that they were intended to preserve useful customs or to conceal important truths; which, had they not been thus embalmed by superstition, could never have been perpetuated for the use and advantage of posterity. I shall illustrate this assertion by one or two examples. Whenever the ancients proposed to build a town, or to pitch a camp, a sacrifice was offered to the gods, and the Soothsayer declared, from the appearance of the entrails, whether they were propitious or not to the design. What was this but a physiological inquiry into the salubrity of the situation, and the purity of the waters that supplied it? for we well know that in unwholesome districts, especially when swampy, the cattle will uniformly present an appearance of disease in the viscera, which an experienced eye can readily detect; and when we reflect upon the age and climate in which these ceremonies were performed, we cannot but believe that their introduction was suggested by principles of wise and useful policy. In the same manner, Bathing, which at one period of the world, was essentially necessary, to prevent the diffusion of Leprosy, and other infectious diseases, was wisely converted into an act of religion, and the priests persuaded the people that they could only obtain absolution on washing away their sins by frequent ablutions; but since the use of linen shirts has become general, and every one has provided for the cleanliness of his own person, the frequent bath ceases to be so essential, and therefore no evil has arisen from the change of religious belief respecting its connection with the welfare and purity of the soul. Among the religious impurities and rules of purification of the Hindoos, we shall be able to discern the same principle although distorted by the grossest superstition. The ancient custom of erecting “Acerræ” or Altars, near the bed of the deceased, in order that his friends might daily burn Incense until his burial, was long practised by the Romans. The Chinese observe a similar custom; they place upon the altar thus erected an image of the dead person, to which every one who approaches it bows four times, and offers oblations and perfumes. Can there be any difficulty in recognising, in this tribute to the dead, a wise provision for the preservation of the living? The original intention was, beyond doubt, to overcome any offensive smell, and to obviate the dangers that might arise from the emanations of 19the corpse. These instances are sufficient to shew the justness of my position: if time and space would allow, many others of a striking and interesting character might be adduced.^[32]

CREDULITY.

Although it is nearly allied to Superstition, yet it differs very widely from it. Credulity is an unbounded belief in what is possible, although destitute of proof and perhaps of probability; but Superstition is a belief in what is wholly repugnant to the laws of the physical and moral world. Thus, if we believe that an inert plant possesses any remedial power, we are credulous; but if we were to fancy that, by carrying it about with us, we should become invulnerable, we should in that case be superstitious. Credulity is a far greater source of error than Superstition; for the latter must be always more limited in its influence, and can exist only, to any considerable extent, in the most ignorant portion of society; whereas the former diffuses itself through the minds of all classes, by which the rank and dignity of science are degraded, its valuable labours confounded with the vain pretensions of empiricism, and ignorance is enabled to claim for itself the prescriptive right of delivering oracles, amidst all the triumphs of truth, and the progress of philosophy. This is very lamentable; and yet, if it were even possible to remove the film that thus obscures the public discernment, I question whether the adoption of such a plan would not be outvoted by the majority of our own profession. In Chili, says Zimmerman, the physicians blow around the beds of their patients to drive away diseases; and as the people in that country believe that physic consists wholly in this wind, their doctors would take it very ill of any person who should attempt to make the method of cure more difficult—they think they know enough, when they know how to blow.

But this mental imbecility is not characteristic of any age or country. England has, indeed, by a late continental writer,^[33] been accused of possessing a larger share of credulity than its neighbours, and it has been emphatically called “The Paradise of Quacks,” but with as little truth as candour. If we refer to the works of Ætius, written more than 1300 years ago, we shall discover the existence of a similar infirmity with regard to physic. This author has collected a multitude of receipts, particularly those that had been celebrated, or used as Nostrums,^[34] many of which he mentions with no other view than to expose their folly, and to inform us at what an extravagant price they were purchased. We accordingly learn from him that the collyrium of Danaus was sold at Constantinople for 120 numismata, and the cholical antidote of Nicostratus for two talents; in short, we shall find an unbounded credulity with respect to the powers of inert medicines, from the elixir and alkahest of Paracelsus and Van-Helmont, to the tar water of bishop Berkeley, the metallic tractors of Perkins, the animal magnetism of Miss Prescott, and may I not add, with equal justice, to the nitro-muriatic acid bath of Dr. Scott? The 20description of Thessalus, the Roman empiric in the reign of Nero, as drawn by Galen, applies with equal fidelity and force to the medical Charlatan of the present day; and, if we examine the writings of Scribonius Largus, we shall obtain ample evidence that the same ungenerous selfishness of keeping medicines secret, prevailed in ancient no less than in modern times; while we have only to read the sacred orations of Aristides to be satisfied, that the flagrant conduct of the Asclepiades, from which he so severely suffered,^[35] was the very prototype of the cruel and remorseless frauds, so wickedly practised by the unprincipled Quack Doctors and advertising “Medical Boards,” of our own times: and I challenge the apologist of ancient purity to produce a more glaring instance of empirical effrontery and success, in the annals of the nineteenth century, than that of the sacred impostor described in the Alexander of Lucian, who established himself in the deserted temple of Esculapius, and entrapped in his snares some of the most eminent of the Roman senators.

SCEPTICISM.

Credulity has been justly defined, Belief without Reason. Scepticism is its opposite, Reason without Belief and is the natural and invariable consequence of credulity: for it may be generally observed, that men who believe without reason, are succeeded by others whom no reasoning can convince; a fact which has occasioned many extraordinary and violent revolutions in the Materia Medica, and a knowledge of it will enable us to explain the otherwise unaccountable rise and fall of many useless, as well as important articles. It will also suggest to the reflecting practitioner, a caution of great moment, to avoid the dangerous fault imputed to Galen by Dioscorides, of ascribing too many and too great virtues to one and the same medicine. By bestowing unworthy and extravagant praise upon a remedy, we in reality do but detract from its reputation,^[36] and run the risk of banishing it from practice; for when the sober practitioner discovers by experience that a medicine falls so far short of the efficacy ascribed to it, he abandons its use in disgust, and is even unwilling to concede to it that degree of merit to which in truth and justice it may be entitled; the inflated eulogiums bestowed upon the operation of Digitalis in pulmonary 21diseases, excited, for a time, a very unfair impression against its use; and the injudicious manner in which the antisyphilitic powers of Nitric Acid have been aggrandised, had very nearly exploded a valuable auxiliary from modern practice.

It is well known with what avidity the public embraced the expectations given by Stöerk of Vienna in 1760, with respect to the efficacy of Hemlock; every body, says Dr. Fothergill, made the extract, and every body prescribed it, but finding that it would not perform the wonders ascribed to it, and that a multitude of discordant diseases refused to yield, as it was asserted they would, to its narcotic powers, practitioners fell into the opposite extreme of absurdity, and declaring that it could do nothing at all, dismissed it at once as inert and useless. Can we not then predict the fate of the Cubebs, which has been lately restored to notice with such extravagant praise and unqualified approbation? May the sanguine advocates for the virtues of the Colchicum derive a useful lesson of practical caution from these precepts: it would be a matter of regret that a remedy which, under skilful management, certainly possesses considerable virtue, should again fall into obscurity and neglect from the disgust excited by the extravagant zeal of its supporters.

There are, moreover, those who cherish a spirit of scepticism, from an idea that it denotes the exercise of a superior intellect; it must be admitted, that at that period in the history of Europe, when reason first began to throw off the yoke of authority, it required superiority of understanding as well as intrepidity of conduct, to resist the powers of that superstition which had so long held it in captivity; but in the present age, observes Mr. Dugald Stewart, “unlimited scepticism is as much the child of imbecility as implicit credulity.” “He who at the end of the eighteenth century,” says Rousseau, “has brought himself to abandon all his early principles, without discrimination, would probably have been a bigot in the days of the league.”

FALSE THEORIES, AND ABSURD CONCEITS.

He who is governed by preconceived opinions, may be compared to a spectator who views the surrounding objects through coloured glasses, each assuming a tinge similar to that of the glass employed; thus have crowds of inert and insignificant drugs been indebted to an ephemeral popularity, from the prevalence of a false theory; the celebrated hypothesis of Galen respecting the virtues and operation of medicines, may serve as an example; it is a web of philosophical fiction, which was never surpassed in absurdity. He conceives that the properties of all medicines are derived from what he calls their elementary or cardinal qualities, Heat, Cold, Moisture, and Dryness. Each of these qualities is again sub-divided into four degrees, and a plant or medicine, according to his notion, is cold or hot, in the first, second, third, or fourth gradation; if the disease be hot, or cold in any of these four stages, a medicine possessed of a contrary quality, and in the same proportionate degree of elementary heat or cold, must be prescribed. Saltness, bitterness, and acridness depend, in his idea, upon the relative degrees of heat and dryness in different bodies. It will be easily seen how a belief in such an hypothesis must have multiplied the list of inert articles in the materia medica, and have corrupted the practice of physic. The variety of seeds derived its origin from this 22source, and until lately, medical writers, in the true jargon of Galen, spoke of the four greater and lesser hot and cold seeds; and in the London Dispensatory of 1721, we find the powders of hot and cold precious stones, and those of the hot and cold compound powders of pearl. Several of the ancient combinations of opium, with various aromatics, are also indebted to Galen for their origin, and to the blind influence of his authority for their existence and lasting reputation. Galen asserted that opium was cold in the fourth degree, and must therefore require some corresponding hot medicine to moderate its frigidity.^[37]

The Methodic Sect, which was founded by the Roman physician Themison,^[38] a disciple of Asclepiades, as they conceived all diseases to depend upon overbracing, or on relaxation, so did they class all medicines under the head of relaxing and bracing remedies; and although this theory has been long since banished from the schools, yet it continues at this day to exert a secret influence on medical practice, and to preserve from neglect some unimportant medicines. The general belief in the relaxing effect of the warm, and the equally strengthening influence of the cold bath, may be traced to conclusions deduced from the operations of hot and cold water upon parchment and other inert bodies.^[39]

The Stahlians, under the impression of their ideal system, introduced Archœal remedies, and many of a superstitious and inert kind; whilst, as they on all occasions trusted to the constant attention and wisdom of nature, so did they zealously oppose the use of some of the most efficacious instruments of art, as the Peruvian bark; and few physicians were so reserved in the use of general remedies, as bleeding, vomiting, and the like; their practice was therefore imbecile, and it has been aptly enough denominated, “a meditation upon death.” They were however vigilant in observation and acute in discernment, and we are indebted to them for some faithful and minute descriptions.

The Mechanical Theory, which recognised “lentor and morbid viscidity of the blood,” as the principal cause of all diseases, introduced attenuant and diluent medicines, or substances endued with some mechanical force; thus Fourcroy explained the operation of mercury by its specific gravity,^[40] and the advocates of this doctrine favoured the general introduction of the preparations of iron, especially in schirrus of the spleen or liver, upon the same hypothetical principle; for, say they, whatever is 23most forcible in removing the obstruction, must be the most proper instrument of cure; such is Steel, which, besides the attenuating power with which it is furnished, has still a greater force in this case from the gravity of its particles, which, being seven times specifically heavier than any vegetable, acts in proportion with a stronger impulse, and therefore is a more powerful deobstruent. This may be taken as a specimen of the style in which these mechanical physicians reasoned and practised.

The Chemists, as they acknowledged no source of disease but the presence of some hostile acid or alkali, or some deranged condition in the chemical composition of the fluid or solid parts, so they conceived all remedies must act by producing chemical changes in the body. We find Tournefort busily engaged in testing every vegetable juice, in order to discover in it some traces of an acid or alkaline ingredient, which might confer upon it medicinal activity. The fatal errors into which such an hypothesis was liable to betray the practitioner, receive an awful illustration in the history of the memorable fever that raged at Leyden in the year 1699, and which consigned two thirds of the population of that city to an untimely grave; an event which, in a great measure, depended upon the Professor Sylvius de la Boe, who having just embraced the chemical doctrines of Van Helmont, assigned the origin of the distemper to a prevailing acid, and declared that its cure could alone be effected by the copious administration of absorbent and testaceous medicines; an extravagance into which Van Helmont, himself, would hardly have been betrayed:—but thus it is in Philosophy, as in Politics, that the partisans of a popular leader are always more sanguine, and less reasonable, than their master; they are not only ready to delude the world, but most anxious to deceive themselves, and while they warmly defend their favourite system from the attacks of those that may assail it, they willingly close their own eyes, and conceal from themselves the different points that are untenable; or, to borrow the figurative language of a French writer, they are like the pious children of Noah,^[41] who went backwards, that they might not see the nakedness which they approached for the purpose of covering.

Unlike the mechanical physicians, the chemists explain the beneficial operation of iron by supposing that it increases the proportion of red globules in the blood, on the erroneous^[42] hypothesis that iron constitutes the principal element of these bodies. Thus has iron, from its acknowledged powers, been enlisted into the service of every prevailing hypothesis; and it is not a little singular, as a late writer has justly observed, that theories however different, and even adverse, do nevertheless often coincide in matters of practice, as well with each other as with long established empirical usages, each bending as it were, and conforming, in order to do homage to truth and experience. And yet iron, whose medicinal virtues have been so generally allowed, has not escaped those vicissitudes in reputation which almost every valuable remedy has been doomed to suffer: at one period the ancients imagined that wounds inflicted by iron instruments, were never 24disposed to heal, for which reason Porsenna, after the expulsion of the Tarquins, actually stipulated with the Romans that they should not use iron, except in agriculture; and Avicenna was so alarmed at the idea of its internal use as a remedy, when given in substance, that he seriously advised the exhibition of a magnet^[43] after it to prevent any direful consequences. The fame even of Peruvian bark has been occasionally obscured by the clouds of false theory some condemned its use altogether, “because it did not evacuate the morbific matter,” others, “because it bred obstructions in the viscera,” others again, “because it only bound up the spirits, and stopped the paroxysms for a time, and favoured the translation of the peccant matter into the more noble parts.” Thus we learn from Morton,^[44] that Oliver Cromwell fell a victim to an intermittent fever, because the Physicians were too timid to make a trial of the bark. It was sold first by the Jesuits for its weight in silver;^[45] and Condamine relates that in 1690, about thirty years afterwards, several thousand pounds of it lay at Piura and Payta for want of a purchaser.

Nor has Sugar escaped the venom of fanciful hypothesis. Dr. Willis raised a popular outcry against its domestic use, declaring that “it contained within its particles a secret acid—a dangerous sharpness,—which caused scurvys, consumptions, and other dreadful diseases.”^[46]

Although I profess to offer merely a few illustrations of those doctrines, whose perverted applications have influenced the history of the Materia Medica, I cannot pass over in silence that of John Brown, “the child of genius and misfortune.” As he generalized diseases, and brought all within the compass of two grand classes, those of increased and diminished excitement, so did he abridge our remedies, maintaining, that every agent which could operate on the human body was a Stimulant, having an identity of action, and differing only in the degree of its force; so that, according to his views, the lancet and the brandy bottle were but the opposite extremes of one and the same class: the mischievous tendency of such a doctrine is too obvious to require a comment.

But the most absurd and preposterous hypothesis that has disgraced the annals of medicine, and bestowed medicinal reputation upon substances of no intrinsic worth, is that of the Doctrine of Signatures, as it has been called, which is no less than a belief that every natural substance which possesses any medicinal virtue, indicates by an obvious and well-marked external character, the disease for which it is a remedy, or the object for which it should be employed!^[47] This extraordinary monster of the fancy has been 25principally adopted and cherished by Paracelsus, Baptista Porta, and Crollius, although traces of its existence may be certainly discovered in very ancient authors. The root of the Mandrake, from its supposed resemblance to the human form, was esteemed as a remedy for Sterility: thus did Rachael demand from her sister the Mandrakes (Dudaim) which Reuben had gathered in the field; impressed, as it would appear, with a belief in the efficacy of that plant against barrenness.^[48] There would moreover appear in this case to have been some idea of additional virtue arising from the person who gathered it, for great stress was laid upon this circumstance, “my son’s Mandrakes:” such a notion is by no means uncommon in the history of charms. The supposed virtues of the Lapis Ætites, or Eagle stone,^[49] described by Dioscorides, Ætius and Pliny, who assert that if tied to the arm it will prevent abortion, and if fixed to the thigh forward delivery, were, as we learn from ancient authority, solely suggested by the manner in which the nodule contained within the stone moves and rattles, whenever it is shaken. “Ætites lapis agitatus, sonitum edit, velut ex altero lapide prægnans.” The conceit however did not assume the importance of a theory until the end of the fourteenth century, at which period we find several authors engaged in the support of its truth, and it will not be unamusing to offer a specimen of their sophistry; they affirm, that since man is the lord of the creation, all other creatures are designed for his use, and therefore, that their beneficial qualities and excellencies must be expressed by such characters as can be seen and understood by every one; and as man discovers his reason by speech, and brutes their sensations by various sounds, motions, and gestures, so the vast variety and diversity of figures, colours, and consistencies, observable in inanimate creatures, is certainly designed for some wise purpose. It must be, in order to manifest these peculiar qualities and excellencies, which could not be so effectually done in any other way, not even by speech, since no language is universal. Thus, the lungs of a fox must be a specific for asthma, because that animal is remarkable for its strong powers of respiration. Turmerick has a brilliant yellow colour, which indicates that it has the power of curing the jaundice; by the same rule, Poppies must relieve diseases of the head; Agaricus those of the bladder; Cassia fistula the affections of the intestines, and Aristolochia the disorders of the uterus: the polished surface and stony hardness which so eminently characterise the seeds of the Lithospermum Officinale (Common Gromwell) were deemed a certain indication of their efficacy in calculous and gravelly disorders; for a similar reason the roots of the Saxifraga Granulata (White Saxifrage) gained reputation in the cure of the same disease; and the Euphrasia (Eye-bright) acquired fame, as an application in complaints of the eye, because it exhibits a black spot in its corolla resembling the pupil.

In the curious work of Chrysostom Magnenus, we meet with a whimsical account of the Signature of Tobacco. “In the first place,” says he, “the manner in which the flowers adhere to the head of the plant indicates the Infundibulum Cerebri, and Pituitary Gland. In the next place, the three membranes of which its leaves are composed announce their value to the stomach which has three membranes.”^[50]

26The blood-stone, the Heliotropium of the ancients, from the occasional small specks or points of a blood red colour exhibited on its green surface, is even at this day employed in many parts of England and Scotland, to stop a bleeding from the nose; and nettle-tea continues a popular remedy for the cure of Urticaria. It is also asserted that some substances bear the Signatures of the humours, as the petals of the red rose that of the blood, and the roots of rhubarb and the flowers of saffron, that of the bile.^[51]

I apprehend that John of Gaddesden, in the fourteenth century, celebrated by Chaucer, must have been directed by some remote analogy of this kind, when he ordered the son of Edward the First, who was dangerously ill with the small-pox, to be wrapped in scarlet cloth, as well as all those who attended upon him, or came into his presence, and even the bed and room in which he was laid were covered with the same drapery; and so completely did it answer, say the credulous historians of that day, that the Prince was cured without having so much as a single mark left upon him.

In enumerating the conceits of Physic, as relating to the Materia Medica, we must not pass over the idea, so prevalent at one period, that all poisonous substances possess a powerful and mutual elective attraction for each other; and that consequently, if a substance of this kind were suspended around the neck, it would, by intercepting and absorbing every noxious particle, preserve the body from the virulence of contagious matter. Angelus Sala, accordingly, gives us a formula for what he terms his Magnes Arsenicalis, which he asserts will not only defend the body from the influence of poison, but will, from its powers of attraction, draw out the venom from an infected person. In the celebrated plague of London, we are informed that amulets of arsenic were upon this principle suspended over the region of the heart, as a preservative against infection.

There is yet to be mentioned another absurd conceit which long existed respecting the subject of Antidotes,—a belief that every natural poison carried within itself its own antidote; thus we learn from the writings of Dioscorides, Galen, and Pliny, that the virus of the Cantharis Vesicatoria existed in the body of the fly, and that the head, feet, and wings, contained its antidote; for the same potent reason were the hairs of the rabid dog esteemed the true specific for Hydrophobia.^[52]

DEVOTION TO AUTHORITY, AND ESTABLISHED ROUTINE.

This has always been the means of opposing the progress of reason—the advancement of natural truths—and the prosecution of new discoveries; whilst, with effects no less baneful, has it perpetuated many of the stupendous errors which have been already enumerated, as well as others no less weighty, and which are reserved for future discussion.

27To give general currency to an hypothetical opinion, or medicinal reputation to an inert substance, requires only the talismanic aid of a few great names; when once established upon such a basis, ingenuity, argument, and even experiment, may open their ineffectual batteries. The laconic sentiment of the Roman Satirist is ever opposed to our remonstrance—“Marcus dixit?—ita est.”

A physician cannot err, in the opinion of the public, if he implicitly obeys the dogmas of authority; in the most barbarous ages of ancient Egypt, he was punished or rewarded according to the extent of his success, but to escape the former, it was only necessary to shew that an orthodox plan of cure had been followed, such as was prescribed in the acknowledged writings of Hermes. It is an instinct in our nature to follow the track pointed out by a few leaders; we are gregarious animals, in a moral as well as a physical sense, and we are addicted to routine, because it is always easier to follow the opinions of others than to reason and judge for ourselves. “The mass of mankind,” as Dr. Paley observes, “act more from habit than reflection.” What, but such a temper could have upheld the preposterous system of Galen for more than thirteen centuries; and have enabled it to give universal laws in medicine to Europe—Africa—and part of Asia?^[53] What, but authority, could have inspired a general belief, that the sooty washings of rosin^[54] would act as an universal remedy? What, but a blind devotion to authority, or an insuperable attachment to established custom and routine, could have so long preserved from oblivion the absurd medicines which abound in our earlier dispensatories? for example, the “Decoctum ad Ictericos,” of the Edinburgh College, which never had any other foundation than the doctrine of signatures, in favour of the Curcuma and Chelidonium Majus;^[55] and it is only within a few years, that the Theriaca Andromachi, in its ancient absurd form, has been dismissed from the British Pharmocopœia.^[56] The Codex-Medicamentarius of Paris, recently edited, still cherishes this many-headed^[57] 28monster of pharmacy, in all its pristine deformity, under the appropriate title of “Electuarium Opiatum Polupharmacum.”

It is, however, evidently indebted for this unexpected rescue from oblivion to a cause very remote from that which may be at first imagined; not from any belief in its powers or reliance upon its efficacy, but from a disinclination to oppose the torrent of popular prejudice, and to reject what has been established by authority and sanctioned by time. For the same reason, and in violation of their better judgment, the editors have retained the absurd formula of Diest for the preparation of an extract of opium; which, after directing various successive operations, concludes by ordering the decoction to be boiled incessantly for six months, supplying the waste of water at intervals! Many of the compound formulæ in this new Codex, it is frankly allowed, possess an unnecessary and unmeaning, if not an injurious complexity; and yet, such force has habit, and so paramount are the verba magistri, that the editors are satisfied in distinguishing the more important ingredients by printing them in Italics, leaving the rest to be supplied at the whim and caprice of the dispenser, and thus are the grand objects and use of a national Pharmacopœia defeated, which should above all things insure uniformity in the strength and composition of its officinal preparations.

The same devotion to authority which induces us to retain an accustomed remedy for pertinacity, will always oppose the introduction of a novel practice with asperity, unless indeed it be supported by authority of still greater weight and consideration. The history of various articles of diet and medicine will prove in a striking manner, how greatly their reputation and fate have depended upon authority. It was not until many years after Ipecacuan had been imported into Europe, that Helvetius, under the patronage of Louis XIV. succeeded in introducing it into 29practice: and to the eulogy of Katharine, queen of Charles II. we are indebted for the general introduction of Tea into England.^[58]

That most extraordinary plant,^[59] Tobacco, notwithstanding its powers of fascination, has suffered romantic vicissitudes in its fame and character; it has been successively opposed, and commended by physicians—condemned, and eulogised by priests and kings—and proscribed, and protected by governments; whilst at length this once insignificant production of a little island, or an obscure district, has succeeded in diffusing 30itself through every climate, and in subjecting the inhabitants of every country to its dominion. The Arab cultivates it in the burning desert—The Laplander and Esquimaux risk their lives to procure a refreshment so delicious in their wintry solitude—the Seaman, grant him but this luxury, and he will endure with cheerfulness every other privation, and defy the fury of the raging elements; and in the higher walks of civilized society, at the shrine of fashion, in the palace, and in the cottage, the fascinating influence of this singular plant commands an equal tribute of devotion and attachment. The history of the Potatoe is perhaps not less extraordinary, and is strikingly illustrative of the omnipotent influence of authority; the introduction of this valuable plant received, for more than two centuries, an unexampled opposition from vulgar prejudice, which all the philosophy of the age was unable to dissipate, until Louis the XVth wore a bunch of the flowers of the potatoe in the midst of his court, on a day of festivity; the people then for the first time obsequiously acknowledged its utility, and ventured to express their astonishment at the apathy which had so long prevailed with regard to its general cultivation; that which authority thus established, time and experience have fully ratified, and scientific research has extended the numerous resources which this plant is so wonderfully calculated to furnish; thus, its stalk, considered as a textile plant, produces in Austria a cottony flax—in Sweden, sugar is extracted from its root—by combustion its different parts yield a very considerable quantity of potass,—its apples, when ripe, ferment and yield vinegar by exposure, or spirit by distillation—its tubercles made into a pulp, are a substitute for soap in bleaching,—cooked by steam, the potatoe is the most wholesome and nutritious, and, at the same time, the most economical of all vegetable aliments.^[60]—by different manipulations it furnishes two kinds of flour, a gruel, and a parenchyma, which in times of scarcity may be made into bread, or applied to increase the bulk of bread made from grain,—to the invalid it furnishes both aliment and medicine; its starch is not in the least inferior to the Indian arrow root, and Dr. Latham has lately shown that an extract may be prepared from its leaves and flowers, which possesses valuable properties as an anodyne remedy.^[61]

The history of the warm bath^[62] presents us with another curious instance of the vicissitudes to which the reputation of our valuable resources are so universally exposed; that which for so many ages was esteemed the greatest luxury in health,^[63] and the most efficacious remedy in disease, fell into total disrepute in the reign of Augustus, for no other reason than because Antonius Musa had cured the Emperor of a dangerous 31malady by the use of the cold bath. The most frigid water that could be procured was, in consequence, recommended on every occasion: thus Horace, in his epistle to Vala, exclaims—

This practice, however, was doomed but to an ephemeral popularity, for although it had restored the Emperor to health, it shortly afterwards killed his nephew and son in law, Marcellus; an event which at once deprived the remedy of its credit, and the physician of his popularity.

The history of the Peruvian Bark would furnish a very curious illustration of the overbearing influence of authority in giving celebrity to a medicine, or in depriving it of that reputation to which its virtues entitle it. This heroic remedy was first brought to Spain in the year 1632, and we learn from Villerobel that it remained for seven years in that country before any trial was made of its powers, a certain ecclesiastic of Alcala being the first person in Spain to whom it was administered in the year 1639; but even at this period its use was limited, and it would have sunk into oblivion but for the supreme power of the Roman church, by whose auspices it was enabled to gain a temporary triumph over the passions and prejudices which opposed its introduction; Innocent the Tenth, at the intercession of Cardinal de Lugo, who was formerly a Spanish Jesuit, ordered that the nature and effects of it should be duly examined, and upon being reported as both innocent and salutary, it immediately rose into public notice;^[64] its career, however, was suddenly stopped by its having unfortunately failed in the autumn of 1652 to cure Leopold, Archduke of Austria, of a Quartan Intermittent; this disappointment kindled the resentment of the prince’s principal physician, Chifletius, who published a violent philippic against the virtues of Peruvian Bark, which so fomented the prejudices against its use, that it had nearly fallen into total neglect and disrepute.

Thus there exists a fashion in medicine, as in the other affairs of life, regulated by the caprice and supported by the authority of a few leading practitioners, which has been frequently the occasion of dismissing from practice valuable medicines, and of substituting others less certain in their effects and more questionable in their nature. As years and fashions revolve, so have these neglected remedies, each in its turn, risen again into favour and notice, whilst old receipts, like old almanacks, are abandoned until the period may arrive, that will once more adapt them to the spirit and fashion of the times. Thus it happens that most of our “New Discoveries” in the Materia Medica have turned out to be no more than the revival and adaptation of ancient practices. In the last century, the root of the Aspidium Filix, the Male Fern, was retailed as a secret nostrum by Madame Nouffleur, a French empiric, for the cure of tape worm; the secret was purchased for a considerable sum of money by Louis XV. and the physicians then discovered that the same remedy had been administered in that complaint by Galen.^[65]

32The history of popular medicines for the cure of Gout, will also furnish us with ample matter for the illustration of this subject. The celebrated Duke of Portland’s Powder was no other than the Diacentaureon of Cælius Aurelianus, or the Antidotos ex duobus Centaureæ generibus of Ætius,^[66] the receipt for which a friend of his Grace brought from Switzerland; into which country it had been probably introduced by the early medical writers, who had transcribed its virtues from the Greek volumes soon after their arrival into the western parts of Europe. The active ingredient of a no less celebrated remedy for the same disease, the Eau Medicinale,^[67] has been discovered to be the Colchicum Autumnale or Meadow Saffron; upon investigating the properties of this medicine, it was observed that similar effects in the cure of the gout were ascribed to a certain plant, called Hermodactyllus^[68] by Oribasius and Ætius, but more particularly by Alexander of Tralles,^[69] a physician of Asia Minor in the fourth century; an inquiry was accordingly instituted after this unknown plant, and upon procuring a specimen of it from Constantinople, it was actually found to be a species of Colchicum.

The use of Prussic acid in the cure of Phthisis, which has been lately proposed by Dr. Majendie, and introduced into the Codex Medicamentarius of Paris, is little else than the revival of the Dutch practice in this complaint; for Linnæus informs us, in the fourth volume of his “Amænitates Academicæ,” that distilled Laurel water was frequently used in Holland for the cure of pulmonary consumption.

The celebrated fever powder of Dr. James was evidently not his original composition, but an Italian nostrum invented by a person of the name of Lisle, a receipt for the preparation of which is to be found at length in Colborne’s Complete English Dispensatory for the year 1756.

The various secret preparations of Opium, which have been extolled as the invention of modern times, may be recognized in the works of ancient authors; for instance, Wedelius in his Opiologia describes an acetic solution; and the Magisterium of Ludovicus, as noticed by Etmuller, was a preparation made by dissolving Opium in vinegar, and precipitating with Salt of Tartar;^[70] Van Helmont recommends a preparation, similar to the black drop, under the title of Laudanum Cydoniatum: then again we have Langelott’s Laudanum, and Le Mort’s “Extract out of Rain water,” preparations which owe their mildness to the abstraction of the resinous element of opium.

33The works of Glauber contain accounts of many discoveries that have been claimed by the chemists of our own day; he recommends the use of muriatic acid in sea scurvy, and describes an apparatus for its preparation exactly similar to that which has been extolled as the invention of Wolff; he also notices the production of Pyro-acetic Acid, under the title of “Vinegar of Wood,” so that the fact of the identity of this acid and Vinegar, so lately announced by Vauquelin as a New Discovery, was evidently known to Glauber nearly two centuries ago.

We have within the last few years heard much of the efficacy of Henbane fumigations in the tooth-ache, an application which may be easily shewn to be the revival only of a very ancient practice.^[71]

But while we might thus proceed to annul many other claims for originality, we ought not to close our eyes to the fallacies to which such investigations are peculiarly exposed. Nothing is more easy than to invest the doubtful sentence of an obscure author with an interpretation best adapted for the support of a favourite theory, and instances might be adduced where the medical antiquarian^[72] has by violence and distortion forced the most contradictory passages into his service; treating, in short, the oracles of Physic just as Lord Peter treated his father’s will in the Tale of a Tub,—determined to discover the word “Shoulder Knots,” he picks it out, letter by letter, and is even at last obliged to substitute C for K in the orthography.

Nor has Fashion confined her baneful interference to the selection of remedies; she has ventured even to decide upon the nature of Diseases, and to change and modify their appellations according to the whim and caprice by which she is governed. The Princess, afterwards Queen Anne, was subject to Hypochondriacal attacks, which her Physicians pronounced to be Spleen, Vapours, or Hyp, and recommended Rawleigh’s Confection, and Pearl Cordial, for its cure: this circumstance was sufficient to render both the Disease and Remedy fashionable; no other complaint was ever heard of in the precincts of the court but that of the Vapours, nor any medicine esteemed but that of Rawleigh. Some years afterwards, 34in consequence of Dr. Whytt’s publication on “Nervous diseases,” a lady of Fashion was pronounced to be Nervous—the term became general, and the disease fashionable; and Spleen, Vapours, and Hyp were consigned to oblivion: the reign of Nervous Diseases, however, did not long continue, for a popular work appeared on Biliary Concretions, and all the world became bilious. We have not patience to pursue the history of these follies; a transient glance at the ephemeral productions of the last twenty years would furnish a sad display of the versatility of medical opinions, and of the instability of the practice which has been founded upon them: and they will no doubt furnish the future historian with strong and forcible illustrations.

THE ASSIGNING TO ART THAT WHICH WAS THE EFFECT OF UNASSISTED NATURE, OR THE CONSEQUENCE OF INCIDENTAL CHANGES OF HABIT, DIET, &c.

Our inability upon all occasions to appreciate the efforts of nature in the cure of disease, must always render our notions, with respect to the powers of art, liable to numerous errors and multiplied deceptions. Nothing is more natural, and at the same time more erroneous, than to attribute the cure of a disease to the last medicine that had been employed; the advocates of amulets and charms^[73] have even been thus enabled to appeal to the testimony of what they call experience, in justification of their superstitions; and cases which, in truth and justice, ought to be considered most lucky escapes, have been triumphantly pronounced as skilful cures; and thus have medicines and practitioners alike acquired unmerited praise, or unjust censure. Upon Mrs. Stephens offering her remedy for the stone to Parliament,^[74] a committee of professional men was nominated to ascertain its efficacy; a patient with stone was selected, and he took the remedy; his sufferings were soon relieved, and upon examining the bladder in the usual way, no stone could be felt, it was therefore agreed that the patient had been cured, and that the stone had been dissolved; some time afterwards this patient died, and on being opened, a large stone was found in a pouch, formed by a part of the bladder, and which communicated with it. When the yellow fever raged in America, the practitioners trusted exclusively to the copious use of mercury; at first, this plan was deemed so universally efficacious, that in the enthusiasm of the moment, it was triumphantly proclaimed that death never took place after the mercury had evinced its effect upon the system: all this was very true, but it furnished no proof of the efficacy of that metal, since the disease, in its aggravated form, was so rapid in its career, that it swept away its victims long before the system could be brought under mercurial influence, while 35in its milder shape it passed off equally well without any assistance from art.

Let us then, before we decree the honours of a cure to a favourite medicine, carefully and candidly ascertain the exact circumstances under which it was exhibited, or we shall rapidly accumulate examples of the fallacies to which our art is exposed; what has been more common than to attribute to the efficacy of a mineral water, those fortunate changes of constitution that have entirely or in great measure, arisen from salubrity of situation, hilarity of mind, exercise of body, and regularity of habits, which have incidentally accompanied its potation. Thus, the celebrated John Wesley, while he commemorates the triumph of ‘Sulphur and Supplication’ over his bodily infirmity, forgets to appreciate the resuscitating influence of four months repose from his apostolic labours; and such is the disposition of the human mind to place confidence in the operation of mysterious agents, that we find him more disposed to attribute his cure to a brown paper plaister of egg and brimstone, than to Dr. Fothergill’s salutary prescription of country air, rest, asses milk, and horse exercise.^[75] The ancient physicians duly appreciated the influence of such agents; their temples, like our watering places, were the resort of those whom medicine could not cure, and we are expressly told by Plutarch that these temples, especially that of Esculapius, were erected on elevated spots, with the most congenial aspects; a circumstance which, when aided by the invigorating effects of hope, by the diversions which the patient experienced in his journey, and perhaps by the exercise to which he had been unaccustomed, certainly performed many cures. It follows then that in the recommendation of a watering place, something more than the composition of a mineral spring is to direct our choice,—the chemist will tell us, that the springs of Hampstead and Islington rival those of Tunbridge and Malvern, that the waters of Bagnigge Wells, as a chalybeate purgative, might supersede those of Cheltenham and Scarborough, and that an invalid would frequent the spring in the vicinity of the Dog and Duck, in St. George’s Fields, with as much advantage as the celebrated Spa at Leamington; but the physician is well aware that by the adoption of such advice, he would deprive his patient of those most powerful auxiliaries to which I have alluded, and above all, lose the advantages of the “Medicina Mentis.” On the other hand, the recommendation of change of air and habits will rarely inspire confidence, unless it be associated with some medicinal treatment; a truth which it is more easy and satisfactory to elucidate and enforce by examples than by precept—let the following story by Voltaire serve as an illustration.—“Ogul, a voluptuary who could be managed but with difficulty by his physician, on finding himself extremely ill from indolence and intemperance, requested advice:—‘Eat a Basilisk, stewed in rose-water,’ replied the physician. In vain did the slaves search for a Basilisk, until they met with Zadig, who, approaching Ogul, exclaimed, ‘Behold that which thou desirest;’ ‘but, my Lord,’ continued he, ‘it is not to be eaten; all its virtues must enter through thy pores, I have therefore enclosed it in a little ball, blown up, and covered with a fine skin; thou must strike this ball with all thy might, and I must strike it back again, for a considerable time, and by observing this regimen, and taking no other drink than rose-water for a few days, thou wilt see, 36and acknowledge the effect of my art.’ The first day Ogul was out of breath, and thought he should have died from fatigue; the second he was less fatigued, and slept better: in eight days he recovered all his strength; Zadig then said to him, ‘There is no such thing in nature as a Basilisk! but thou hast taken exercise and been temperate, and hast therefore recovered thy health!’ But the medical practitioner may perhaps receive more satisfaction from a modern illustration; if so, the following anecdote, related by Sydenham, may not be unacceptable. This great physician having long attended a gentleman of fortune with little or no advantage, frankly avowed his inability to render him any farther service, adding at the same time, that there was a physician of the name of Robinson, at Inverness, who had distinguished himself by the performance of many remarkable cures of the same complaint as that under which his patient laboured, and expressing a conviction that, if he applied to him, he would come back cured. This was too encouraging a proposal to be rejected; the gentleman received from Sydenham a statement of his case, with the necessary letter of introduction, and proceeded without delay to the place in question. On arriving at Inverness, and anxiously enquiring for the residence of Dr. Robinson, he found to his utter dismay and disappointment, that there was no physician of that name, nor ever had been in the memory of any person there. The gentleman returned, vowing eternal hostility to the peace of Sydenham; and on his arrival at home, instantly expressed his indignation at having been sent on a journey of so many hundred miles for no purpose. “Well,” replies Sydenham, “are you better in health?”—“Yes, I am now quite well, but no thanks to you,”—“No,” says Sydenham, “but you may thank Dr. Robinson for curing you. I wished to send you a journey with some object of interest in view; I knew it would be of service to you; in going you had Dr. Robinson and his wonderful cures in contemplation; and in returning, you were equally engaged in thinking of scolding me.”

AMBIGUITY OF NOMENCLATURE.

It has been already stated that we are to a great degree ignorant of the Simples used by the ancient Physicians; we are often quite unable to determine what the plants are of which Dioscorides treats. It does not appear that out of the 700 plants of which his Materia Medica consists, that more than 400 are correctly ascertained; and yet no labour has been spared to clear the subject of its difficulties; Cullen even laments that so much pains should have been bestowed upon so barren an occasion.^[76] The early history of botany presents us with such a chaos of nomenclature, 37that it must have been impossible for the herbarist and physician to have communicated their mutual lights; every one was occupied with disputes upon words and names, and every useful inquiry was suspended, from an inability to decide what plant each author intended; thus, for instance, the Herba Britannica of Dioscorides and Pliny, so celebrated for the cure of the soldiers of Julius Cæsar on the Rhine, of a disease called ‘Scelotyrbe’, and supposed to resemble our sea scurvy, remains quite unknown, notwithstanding the labours of our most intelligent commentators.^[77] It seems also very doubtful whether the plant which we denominate Hemlock was the poison usually administered at the Athenian executions,^[78] and which deprived Socrates and Phocion of life. Pliny informs us that the word Cicuta, amongst the ancients, was not indicative of any particular species of plant, but of vegetable poisons in general; this is a circumstance to which I am particularly anxious to fix your attention; it is by no means uncommon to find a word which is used to express general characters, subsequently become the name of a specific substance in which such characters are predominant; and we shall find that some important anomalies in nomenclature may be thus explained. The term ‘Αρσενικον,’ from which the word Arsenic is derived, was an ancient epithet, applied to those natural substances which possessed strong and acrimonious properties, and as the poisonous quality of arsenic was found to be remarkably powerful, the term was especially applied to Orpiment, the form in which this metal more usually occurred. So the term Verbena (quasi Hebena) originally denoted all those herbs that were held sacred on account of their being employed in the rites of sacrifice, as we learn from the poets;^[79] but as one herb was usually adopted upon these occasions, the word Verbena came to denote that particular herb only, and it is transmitted to us to this day under the same title, viz. Verbena, or Vervain, and indeed until lately it enjoyed the medical reputation which its sacred origin conferred upon it, for it was worn suspended around the neck as an amulet. Vitriol, in the original application of the word, denoted any crystalline body with a certain degree of transparency (Vitrum); it is hardly necessary to observe that the term is now appropriated to a particular species: in the same manner, Bark, which is a general term, is applied to express one genus, and by way of eminence, it has the article, The, prefixed, as The Bark: the same observation will apply to the word Opium, which in its primitive sense signifies any juice (οπος Succus) while it now only denotes one species, viz. that of the Poppy. So again, Elaterium 38was used by Hippocrates, to signify various internal applications, especially purgatives of a violent and drastic nature (from the word ‘Ελαυνω,’ agito, moveo, stimulo), but by succeeding authors it was exclusively applied to denote the active matter which subsides from the juice of the wild cucumber. The word Fecula, again, originally meant to imply any substance which was derived by spontaneous subsidence from a liquid, (from fæx, the grounds or settlement of any liquor); afterwards it was applied to Starch, which is deposited in this manner by agitating the flour of wheat in water; and lastly, it has been applied to a peculiar vegetable principle, which like starch^[80] is insoluble in cold, but completely soluble in boiling water, with which it forms a gelatinous solution; this indefinite meaning of the word fecula has created numerous mistakes in pharmaceutic chemistry; Elaterium, for instance, is said to be a fecula, and in the original sense of the word it is properly so called, inasmuch as it is procured from a vegetable juice by spontaneous subsidence, but in the limited and modern acceptation of the term, it conveys an erroneous idea; for instead of the active principle of the juice residing in fecula, it is a peculiar proximate principle, sui generis, to which I have ventured to bestow the name of Elatin. For the same reason, much doubt and obscurity involve the meaning of the word Extract, because it is applied generally to any substance obtained by the evaporation of a vegetable solution, and specifically to a peculiar proximate principle, possessed of certain characters, by which it is distinguished from every other elementary body—See Extracta. On the other hand, we find that many words which were originally only used to denote particular substances, have, at length, become subservient to the expression of General Characters; thus the term Alkali, in its originally sense, signified that particular residuum which was alone obtained by lixiviating the ashes of the plant named Kali, but the word is now so generalized that it denotes any body possessed of a certain number of definite properties.

Another source of botanical ambiguity and error is the circumstance of certain plants having acquired the names of others very different in their nature, but which were supposed to possess a similarity in external character; thus our Potatoe,^[81] (Solanum Tuberosum) when it was first imported into England by the colonists in the reign of Queen Elizabeth, gained its appellation from its supposed resemblance to an esculent vegetable at that time in common use, under the name of the Sweet Potatoe (Convolvulus Battatas,) and which, like Eringo Root, had the reputation of being able to restore decayed vigour, thus Falstaff—

A similar instance is presented to us in the culinary vegetable well known under the name of the Jerusalem Artichoke, which derived its 39appellation in consequence of its flavour having been considered like that of the common artichoke; it is hardly necessary to observe that it has no botanic relation whatever to such a plant, it being an Heliotrope (Heliotropium Tuberosum), the epithet Jerusalem is a curious corruption of the Italian term Gira-Sole, that is, turn-sun, in English, or Heliotrope in Greek. This instance of verbal corruption is not solitary in medical botany; Castor Oil will suggest itself as another example; this oil, from its supposed efficacy in curing and assuaging the unnatural heat of the body, and in soothing the passions, was called by the French Agnus Castus, whence the inhabitants of St. Kitt’s in the West Indies, who were formerly blended with the French in that Island, called it Castor oil. In some cases again, a plant has received a modern name, compounded of two ancient ones; it appears from Pliny that the Assarum was not uncommonly confounded with the Baccharis; an English name was accordingly bestowed upon it, which is a curious compromise of the question, for it is a compound of both, viz. Assara-bacca.

In some instances the most alarming mistakes have occurred from substances of a very different nature having been mentioned under similar names, Arsenic for instance, has actually been inhaled,^[82] together with the vapours of Frankincense, Myrrh, and those of other gums, during a paroxysm of Asthma! a practice which arose from the practitioner having confounded the Gum Juniper, or Vernix of the Arabians, which was prescribed for fumigations under the name of Sandarach, with the Σανδαρακη of Aristotle, and which was a sulpheret of Arsenic. The gum which we know at the present day under the name of Sanguis Draconis, or Dragon’s blood, was called by the ancient Greeks Κινναβαρὶ, a term which has been incorrectly transferred to a Sulphuret of Mercury, for no other reason than because this mineral has the same red colour as the gum.

The advanced state of Botanical Science will now prevent the recurrence of those doubts and difficulties which have formerly embarrassed the history of vegetable remedies, by furnishing a strictly philosophical language, independent of all theory, and founded upon natural structure, and therefore necessarily beyond the controul of opinion; while the advancement of chemical knowledge, by enabling us better to distinguish and identify the different substances we employ, will also materially assist in preventing the confusion which has formerly oppressed us. At the same time, I am unwilling to join in the commendations so liberally bestowed upon our chemical nomenclature; nay, I am disposed to consider it as a matter of regret that the names of our medicinal compounds should have any relation to their chemical composition, for in the present unsettled state of this science, such a language must necessarily convey theory instead of truth, and opinions rather than facts; in short, it places us at the mercy and disposal of every new hypothesis, which may lay our boasted 40fabric in ruins, and in its place raise another superstructure, equally frail in its materials and ephemeral in its duration: thus Corrosive Sublimate was a muriate of Mercury, or an oxy-muriate, until Sir H. Davy established his new theory of chlorine, and then it became a bi-chloride; at some future period, Chlorine will be found to be a compound, and then it must have another name; for the same reason the term Calomel,^[83] is surely to be preferred to sub-muriate, or Chloride. Tartarized Antimony, again, has been called by our nomenclatural reformers the Tartrate of Antimony and Potass; but is it a triple compound? Gay Lussac thinks not, and considers it as a combination, in which Cream of Tartar acts the part of a simple acid.

Again,—we have only to revert to the nomenclature of the Salts in our Materia Medica to discover the actual change in meaning which the same word has undergone in a very few years. It was originally understood that the term Sub, when prefixed to the generic name of a Salt, indicated the presence of certain qualities depending upon an excess of base; but now, forsooth, the term has reference only to atomic composition, without any regard to qualities.^[84] That salt alone being acknowledged as a true Sub-salt, in which there is less than one atom of acid to each atom of base; thus our “Sub-carbonate of Soda,” is no longer considered a Sub-salt, for the reason above stated; and notwithstanding the predominance of its alkaline characters, it is known to chemists by the appellation of Carbonate of soda. It is far from my intention to question the propriety of these changes, I only maintain that, amidst such chemical doubts, the Pharmaceutist is the last person who should become arbiter; let him await the issue in unobtrusive silence, and take care that the language of Pharmacy partakes of the same neutrality.

Such was the feeling of the Committee appointed by the College for the revision of the late London Pharmacopœia, and it sufficiently explains why the nomenclature of the alkaline salts has been left unchanged in the present edition of that work.

The French, in their new Codex, are absurdly extravagant in their application of chemical nomenclature; thus, the sub-carbonate of potass is called by them sub-deuto-carbonas potassii. The first part of this quadruple name indicates the comparative quantity of acid in the salt, the second that of oxygen contained in the base, the thud announces the acid, and the fourth the basis of the base!

It has been just stated, that we have derived from botanical science a philosophical language which enables us to describe the structure and habits of any plant, with a luminous brevity and an unerring perspicuity; but we are moreover indebted to botany for another service no less important to the successful investigation of the Materia Medica,—that of throwing into well defined groups, those plants which possess obvious natural affinities, and which will be found at the same time to present certain medicinal analogies; indeed, as a general rule, we may admit the axiom, “Quæ genere conveniunt, virtute conveniunt.”^[85]

The Umbelliferæ which grow on dry ground are aromatic, whilst the aquatic species are among the most deadly poisons. The Cruciform plants are aromatic and acrid in their nature, containing essential oils, (hence the peculiar smell of cabbage-water, &c.) which are obtainable by distillation; and Linnæus asserts that “among all the Leguminous or Papilionaceous tribe there is no deleterious plant to be found:” this however is not exactly true. Some of the individuals in these natural orders, although very nearly related, do nevertheless possess various, and even opposite qualities; in the leguminous tribe above mentioned, which is as consistent as any one we possess, we have the Cytisus Laburnum, the seeds of which are violently emetic, and those of Lathyrus Sativus, which have been supposed at Florence to soften the bones and cause death.

In the subdivision of a genus there is often a remarkable difference in the properties of the species; there are, for instance, Solanums, Lettuces, Cucumbers, and Mushrooms, both esculent and poisonous. The Digitalis or Foxglove, and the Verbascum, or common Mullein of our fields, are included in the same Natural family, and yet the one is as active, as the other is mild in its effects; the plants of the natural family of Contortæ abound with a highly acrid milky juice, but Dr. Afzelius met with a shrub of this order at Sierra Leone, the milk of whose fruit was so sweet, as well as copious, as to be used instead of cream for tea; this is certainly what no one could have guessed from analogy. The same individual will vary from culture or other circumstances, as much as any two plants which have no botanic affinity; the Chamomile, Anthemis Nobilis, with which we are well acquainted, may have its whole disk changed by cultivation, to ligulate white florets, destitute of medicinal properties. But, what is more embarrassing, the different parts of the same plant have 42often very different powers; a fact which is beautifully exemplified in the Podophyllum Peltatum, or May Apple, the leaves of which are poisonous, the root powerfully cathartic, and the fruit agreeably esculent; so the leaves of the Jatropa Manihot are employed as a common esculent, while its root secretes a most virulent poison; but we need not seek further for an example than the fruit of the Lemon, the juice of which is acid, its seeds bitter, and its rind aromatic; in some instances it happens that the energy of a plant is concentrated in one particular part, and that all the rest is absolutely inert; thus, the root of the Convolvulus Scammonia, is the only portion of that plant which possesses any medicinal quality;^[86] and the tree which yields the drastic Camboge, presents at the same time an esculent fruit, which is eaten by the natives with as much impunity as the orange; yet, notwithstanding all these difficulties, botany is capable of furnishing us with analogies which will lead to important conclusions with respect to the medicinal properties of different vegetables.

The system of Linnæus, although in a great degree artificial, corresponds in a surprising manner with the natural properties of plants; thus a plant whose calyx is a double valved glume, with three stamina, two pistils, and one naked seed, bears seeds of a farinaceous and nutritious quality; a flower with twelve, or more stamina, all of which are inserted in the internal side of the calyx, will furnish a wholesome fruit; whereas a plant whose flower has five stamina, one pistil, one petal, and whose fruit is of the berry kind, may at once be pronounced as poisonous.

It is also in a great degree true that the sensible qualities of plants, such as colour, taste, and smell, have an intimate relation to their properties, and may often lead by analogy to an indication of their powers; we have an example of this in the dark and gloomy aspect of the Luridæ, which is indicative of their narcotic and very dangerous qualities, as Datura, Hyoscyamus, Atropa, and Nicotiana. Colour is certainly in many cases a test of activity; the deepest coloured flowers of the Digitalis, for example, are the most active, and when the leaves of powerful plants lose their green hue, we may conclude that a corresponding deterioration has taken place with respect to their virtues; but Linnæus ascribed too much importance to such an indication, and his aphorisms are unsupported by facts; for instance, he says “Color pallidus insipidum, viridis crudum, luteus amarum, ruber acidum, albus dulce, niger ingratum, indicat.”^[87] A peculiar heavy odour, which is well known, but is with difficulty defined, is a sure indication of narcotic properties. Bitterness, when not extreme, denotes a tonic quality, which will stimulate the stomach and intestines, and promote the process of digestion. When the bitterness is more intense and pungent,^[88] as in Aloes, Colocynth, &c. we may infer that such substances will produce a more active effect upon the primæ viæ, and that catharsis will follow their administration.

Botanical, like human physiognomy, may frequently afford an insight into character, but it is very often a fallacious index. With regard to the indications of Smell and Taste, it may be observed that in the examination 43of an unknown substance we instinctively apply to these senses for information respecting its properties. It is certainly reasonable to suppose, that those bodies which produce upon the organs of taste a sensible, astringent, or pungent effect, may occasion an impression, corresponding in degree upon the stomach or intestines, which are but an extension of the same structure. But what numerous exceptions are there to such a law? nay, some of the most poisonous substances affect in a very slight degree the organs of taste, especially those that belong to the mineral kingdom, as Arsenious Acid, Oxyd of Antimony, Calomel, &c.; yet some of these are, perhaps, but apparent exceptions, depending upon the degree of solubility which they possess, in consequence of which their energies are not developed until they have traversed a considerable portion of mucous surface. Nor ought it to be forgotten, that cultivation and artificial habits may have blunted the natural susceptibility of our organs, and in some instances changed and depraved their functions: certain qualities for instance are so strongly connected with each other by the chain of association, that by presenting only one to the mind, the other links follow in succession.^[89] It has been remarked, that persons in social life, are more affected by vegetable odours, while the Savage smells better the putrid and fœtid exhalations of animal bodies:^[90] thus the people of Kamskatcha, did not smell the perfume of a vegetable Essence (Aqua Melissæ,) but they discovered by their olfactory sense, a rotten fish, or a stranded whale at a considerable distance.^[91] There is no sense more under the dominion of imagination, or more liable to be perverted by education, than those of taste and smell; we are also liable to form unjust prejudices from the indications of colour; for particular colours, from the influence of hidden associations, are not unfrequently the exciting cause of agreeable or unpleasant impressions. I have met with a person who regards green food, if it be of an animal nature, with unconquerable aversion and disgust, indeed an idea of unwholesomeness has not unfrequently been attached to this colour, without the least foundation of truth; the bones of the Gar fish, or Sea Needle, (Esox Helone,) have been deemed unwholesome from the circumstance of their turning green on being boiled, although not a single instance can be adduced in which that fish ever occasioned any harm. I have met with persons who have been made violently sick from 44eating the green part of the oyster;^[92] an effect which can have no other cause than that of unjust prejudice; these examples are sufficient to shew, with what caution such indications respecting the medicinal qualities of bodies are to be received.

THE APPLICATION AND MISAPPLICATION OF CHEMICAL SCIENCE.

Amongst the researches of different authors, who, animated with a sacred zeal for ancient learning, have endeavoured to establish the antiquity of chemical science, we find many conclusions deduced from an ingenious interpretation of the mythological fables^[93] which are supposed to have been transmitted by the Egyptians; who, previous to the invention of letters, adopted this method of perpetuating their discoveries in natural philosophy. Thus, wherever Homer studiously describes the stolen embraces of Mars and Venus, they recognise some chemical secret, some combination of iron with copper, shadowed in the glowing ornaments of fiction. Lord Bacon^[94] conceived that the union of spirit and matter was allegorised in the fable of Proserpine being seized by Pluto as she was gathering flowers; an allusion, says Dr. Darwin, which is rendered more curiously exact by the late discovery, that pure air, (oxygen) is given out by vegetables, and that in this state it is greedily absorbed by inflammable bodies. The same ingenious Poet supposes that the fable of Jupiter and Juno, by whose union the vernal showers were said to be produced, was meant to pourtray the production of water by the combination of its two elements; an opinion which, says he, is strongly supported by the fact that, in the ancient mythology, the purer air or æther, was always represented by Jupiter, and the inferior by Juno. Were the elegant author of the Botanic Garden now living, he would, no doubt, with a taste and delicacy peculiarly his own, avail himself of the singular discovery of Mr. Smithson, who has detected in the juice of the mulberry two distinct species of colouring matter;—the mingled blood of the unfortunate Pyramus and Thisbe:

Sir William Drummond, the learned apologist of Egyptian science, conceives that the laws of latent heat were even known to the philosophers 45of that ancient nation, and that caloric in such a state, was symbolically represented by Vulcan, while free or sensible caloric was as clearly described in the character of Vesta. Those who maintain the antiquity of chemistry, and suppose that the fabulous conceptions of the ancients were but a mysterious veil ingeniously thrown by philosophy between nature and the lower order of people, consider that the alchemical secret is metaphorically concealed in the fable of the Golden Fleece of the Argonauts, and reject the more probable solution of this story by Strabo, who says that the Iberians, near neighbours of the Colchians, used to receive the gold, brought down from the high lands by the torrents, into sieves and sheep skins, and that from thence arose the fable of the golden fleece. Dionysius, of Mytilene, offers a different explanation of the fable, and supposes it to allude to a book written on skins, and containing an account of the process of making gold according to the art of alchemy.

Notwithstanding the confidence with which modern philosophers have claimed the discovery, the experimental mode of investigation was undoubtedly known and pursued by the ancients, who appear, says Mr. Leslie,^[95] to have concealed their notions respecting it, under the veil of allegory. Proteus signified the mutable and changing forms of material objects, and the inquisitive philosopher was counselled by the Poets^[96] to watch their slippery demon when slumbering on the shore, to bind him, and compel the reluctant captive to reveal his secrets. This, adds Mr. Leslie, gives a lively picture of the cautious, but intrepid advances of the skilful experimenter;—he tries to press nature into a corner,—he endeavours to separate the different principles of action,—he seeks to concentrate the predominant agent, and labours to exclude, as much as possible, every disturbing influence.

But with whatever ingenuity and success the antiquity of chemical knowledge may be advocated, as it relates to the various arts of life, yet it must be allowed that not the most remote trace of its application to physic can be discovered in the medical writers of Greece or Rome. The operation of distillation^[97] is not even mentioned by Hippocrates or Galen; and the waters of different plants, as described by some later authors, are to be understood, as we are informed by Gesner, merely as simple decoctions, and not as the products of any chemical process; while the Essences of Dioscorides, Galen, Oribasius, and others, were only the extracts produced by the evaporation of such infusions.

Upon the downfall of the Roman Empire, all the sciences, the arts, and literature, were overwhelmed in the general wreck, and the early Mahometans, in the first paroxysms of their fanaticism, endeavoured to destroy every record of the former progress of the human mind; consigning to destruction, by the conflagration of the Alexandrian library, no less than seven hundred thousand volumes, which comprised the most valuable works of science and literature.^[98] It is not a little extraordinary that this 46same people were destined at a more advanced period, to rekindle the light of letters,^[99] which they had taken such pains to extinguish, and to become the inventors and cultivators of a new science, boundless in its views, and inexhaustible in its applications. The medical profession too was more particularly selected as an object of reward and encouragement; and we may say, with much truth, that our Materia Medica is more indebted to the zeal and industry of the Arabians, than to the learning of the Greeks, or to the refinement of the Romans. From this source we have acquired the milder purges of Manna, Cassia, Senna, Rhubarb, and many plants and oriental aromatics, amongst, which we may notice Musk, Nutmeg, Mace, and Cloves; the introduction of which into medicine was greatly facilitated by the situation of Bagdat, and its connection with India; and although Archigenes and Aretæus had long before applied Blisters, yet it is to the Arabian physicians that we are indebted for a practical acquaintance with their value, for in general, the Greeks and Romans prescribed acrid Sinapisms for such a purpose. We are also indebted to the Arabians for our knowledge respecting Camphor, as its name imports, for the original word was Cafur or Canfur.^[100] They are also the first upon record, who speak of sugar, and sugar-candy, extracted from the sugar-cane, which they call honey of cane; and they ushered into practice Syrups, Juleps, and Conserves. At the same time, it is but just to allow, that from the disgusting ostentation of this people, and their strong attachment to the marvellous, many absurd medicines have been introduced. Gold, Silver, Bezoars, and precious stones were received into their materia medica, and surprising virtues were attributed to them. Amongst a people thus disposed to magnificence, and from the very spirit of their religion credulous and romantic, it is not a matter of surprise that their first researches into the nature of bodies should have raised a hope, and excited a belief, that the baser metals might be converted into gold.

They conceived that gold was the metallic element, in a state of perfect purity, and that all the other metals differed from it in proportion only to the extent of their individual contamination, and hence the origin of the epithet base, as applied to such metals; this hypothesis explains the origin of alchemy; but, in every history, we are informed that the earlier alchemists expected, by the same means that they hoped to convert the baser metals into gold, to produce a universal remedy, calculated to prolong indefinitely the span of human existence.

It is difficult to imagine what connection could exist in their ideas between the “Philosopher’s Stone,” which was to transmute metals, and a remedy which could arrest the progress of bodily infirmity: upon searching into the writings of these times, it clearly appears that this conceit originated with the alchemists from the application of false analogies, and that the error was subsequently diffused and exaggerated by a misconstruction of alchemical metaphors.^[101]

47An example of reasoning by false analogy is presented to us by Paracelsus, in his work de vita longa, wherein, speaking of anatomy, he exclaims: “Sicut antimonium finit aurum, sic, eadem ratione et forma, corpus humanum purum reddit.”

The processes of alchemy were always veiled in the most enigmatic and obscure language; the earliest alchemist whose name has reached posterity, is Geber, an Arabian prince of the seventh century, whose language was so proverbially obscure, that Dr. Johnson supposes the word gibberish or geberish to have been derived from this circumstance; sometimes the processes of alchemy were expressed by a figurative and metaphorical style of description; thus Geber exclaims, “Bring me the six lepers that I may cleanse them;” by which he implied the conversion of the six metals,^[102] the only ones then known, into gold. From the works of later alchemists it also appears that they constantly represented gold as a sound, healthy, and durable man, the imperfect metals as diseased men, and the means or processes by which the latter were to be transmuted into the former, they designated by the name of medicines; and hence, those who were anxious to dive into the secrets of these magicians, or Adepts, as they termed themselves, without possessing a key to their language, supposed that these descriptions were to be understood in a literal sense, and that the imperfect metals might be changed into gold, and the bodies of sick persons into healthy ones, by one and the same chemical preparation.

The hieroglyphical style of writing adopted by the earlier alchemists, was in a great degree supported by the prevailing idea that the elements were under the dominion of spiritual beings, who might be submitted to human power; and Sir Humphry Davy has observed that the notions of fairies, and of genii, which have been depicted with so much vividness of fancy and liveliness of description in The Thousand and One Nights, seem to have been connected with the pursuit of the science of transmutation, and the production of the elixir of life. That the Arabian Nights’ Entertainment admits of a mystic interpretation, is an opinion which I have long entertained. How strikingly is the effect of fermented spirit, in banishing the pressure of the melancholy which occurs in solitude, depicted in the story of Sinbad when he encountered the withered and decrepid hag, on the uninhabited island—but, to return from this digression to the subject of medical chemistry.

It was not in fact until several years had elapsed in the delusive researches of alchemy, that the application of chemical knowledge became instrumental in the advancement of the medical art. Rhases and Avicenna, who were the celebrated physicians of the age, are the first who introduced pharmaceutical preparations into their works, or made any improvement in the mode of conducting pharmaceutical processes. Avicenna describes, particularly, the method of conducting Distillation; he 48mentions also, for the first time, the three Mineral Acids, and distinguishes between the vegetable and mineral Alkalies; he speaks likewise of the Distilled Water of Roses, of Sublimed Arsenic, and of Corrosive Sublimate.

In the year 1226, Roger Bacon, a native of Ilchester in Somersetshire, and a Franciscan monk of Westminster Abbey, laid the foundations of chemical science in Europe; his discoveries were so extraordinary that he was excommunicated by the Pope, and imprisoned ten years for supposed dealings with the devil; it appears that he was a believer in an universal Elixir, for he proposed one to Pope Clement the Tenth, which he extolled highly, as the invention of Petro de Maharncourt.

This wonderful man was succeeded at the end of the same century by Arnoldus de Villa Nova, a Frenchman, or as others assert, a Spaniard, who deserves to be noticed on this occasion, as being the first to recommend the distilled spirit of wine, impregnated with certain herbs, as a valuable remedy; from which we may date the introduction of Tinctures into medical practice; for, although Thaddæus, a Florentine, who died in 1270, at the age of eighty, bestows great commendation upon the virtues of Spirit of Wine, yet he never used it as a solvent for active vegetable matter.

It was not however until the end of the thirteenth century, that Chemistry can be said to have added any considerable power to the arm of Physic.

Basil Valentine, a German Benedictine monk, led the way to the internal administration of metallic medicine, by a variety of experiments on the nature of Antimony, and in his “Currus Triumphalis Antimonii,” a work written in high Dutch, he has described a number of the combinations of that metal. If however we may credit a vague tradition, he was extremely unfortunate in his first experiments upon his brother monks, all of whom he injured if not killed; those who have keen ears for etymological sounds will instantly recognise, in this circumstance, the origin of the word Antimony,—ἁντί Μονοχους.

It appears that the ancients were ignorant of the internal use and administration of the metals, with the exception of iron, although they frequently used them in external applications. Hippocrates recommends Lead in several parts of his works, as an epulotic application, and for other external purposes. Litharge of Gold and Cerusse also entered the composition of several powders extolled by that ancient physician as possessing great efficacy in defluxions of the eyes. Oribasius and Ætius added “Lithargyrium” to several plaisters, and the composition of the “Snow-like plaister,” from Minium, was long preserved amongst their most valuable secrets. Whether antimony is the Stimmi or Stibium of the ancients has been a matter of conjecture; for Pliny, in speaking of its preparation observes, “Ante omnia urendi modus necessarius, ne Plumbum fiat.” This plumbum however was evidently the revived metal of Antimony, with which the ancients were unacquainted, and therefore mistook it for Lead; besides, the word Plumbum, like many others which I have before mentioned, was used as a general term; thus, according to Pliny, Tin was called Plumbum album; and Agricola calls Lead Plumbum nigrum.^[103]

The question however is unimportant, for this Stibium was never used 49but as an external Astringent, especially for the purpose of contracting the eye-lids, and thereby of making the eyes appear very large, which has been considered from the most remote antiquity, as a feature of great beauty; thus the epithet βοῶπὶς is constantly applied by Homer to Juno. This practice appears also to have been followed by the Jews, for Jezebel is said to have painted her eye-brows to make the eyes appear big;^[104] the expression also shews that the drug employed was the Stimmi. Εστὶμμὶσατο τους οφθαλμους ἁυτης.

To Basil Valentine we are moreover indebted for the discovery of the Volatile Alkali, and of its preparation from Sal Ammoniac; he also first used mineral acids as solvents, and noticed the production of Ether from Alcohol; he seems also to have understood the virtues of sulphate of iron, for he says, when internally administered, it is tonic and comforting to a weak stomach, and that externally applied, it is astringent and styptic: he moreover recommended a fixed alkali made from vine twigs cut in the beginning of March, for the cure of gout and gravel.

In the year 1493, was born near Zurich in Switzerland, Paracelsus, or as he termed himself, Philippus, Theophrastus, Bombastus, Paracelsus de Hohenheim, a man who was destined to produce a greater revolution in the Materia Medica, and a greater change in medical opinions and practice, than any person who had appeared since the days of Galen. He travelled all over the Continent of Europe to obtain knowledge in Chemistry and Physic, and was a great admirer of Basil Valentine, declaring that Antimony was not to be equalled for medicinal virtue, by any other substance in nature: this opinion however does not deserve our respect, for it was not founded upon observation and experiment, but on a fanciful analogy, derived from a property which this metal possesses of refining gold, as I have before related. He also used Mercury without reserve, and appears to have been the first who ventured to administer it internally,^[105] for although Avicenna asserts that it was not so poisonous as the ancients had imagined, yet he does not attribute to it any virtues; he merely says, “Argentum quidem vivum, plurimi qui bibunt, non læduntur eo.” Its effects, when applied externally, were well known to Theodoric the friar, afterwards Bishop of Cervia, in the twelfth century, who describes the salivation which mercurial frictions will produce. Paracelsus, moreover, employed Lead internally in fevers,—“Saturnus purgat febres” was one of his most favourite maxims. He also gives us directions for the preparation of Red Precipitate with Mercury and Aqua fortis.

Paracelsus, thus armed with opium, mercury, and antimony, remedies of no trifling importance, travelled in all directions and performed many extraordinary cures, amongst which was that of the famous printer Frobenius of Basil, a circumstance which immediately brought him acquainted with Erasmus,^[106] and made him known to the magistracy of Basil, 50who elected him professor of chemistry in the year 1527, which was the first professorship that was established in Europe for the promotion and dissemination of chemical science. But notwithstanding this testimony of his success, if we may credit Libavius, he often, like our modern quacks, left his patients more diseased than he found them; and it is acknowledged by his own disciple Oporinus, that when he was sent for to any town, for the purpose of administering his remedies, he was rarely suffered to protract his visit, on account of the general resentment of the inhabitants.

While seated in his chair, he burnt with great solemnity the writings of Galen and Avicenna, and declared to his audience that if God would not impart the secrets of physic, it was not only allowable but even justifiable to consult the devil. His cotemporary physicians he treated with the most sottish vanity and illiberal insolence; in the preface to his work entitled “Paragranum,” he tells them “that the very down of his bald pate had more knowledge than all their writers, the buckles of his shoes more learning than Galen and Avicenna, and his beard more experience than all their Universities.” With such a temper it could not be supposed that he would long retain his chair, in fact he quitted it in consequence of a quarrel with the magistrates, after which he continued to ramble about the country, generally intoxicated, and seldom changing his clothes, or even going to bed; and although he boasted of possessing a Panacea which was capable of curing all diseases in an instant, and even of prolonging life to an indefinite length, yet this drunkard and prince of empirics died after a few hours illness, in the forty-eighth year of his age, at Salzburg in Bavaria, with a bottle of his immortal Catholicon in his pocket.

In contemplating the career of this extraordinary man, it is difficult to say whether disgust or astonishment is the most predominant feeling; his insolence and unparalleled conceit, his insincerity, and brutal singularities, and his habits of immorality and debauchery, are beyond all censure; whilst the important services he has rendered mankind, by opposing the bigotry of the schools and introducing powerful remedies into practice, cannot be recorded without feelings of gratitude and respect: but in whatever estimation Paracelsus may be held, there can be no doubt but that his fame produced a very considerable influence on the character of the age, by exciting the envy of some, the emulation of others, and the industry of all.^[107]

About a century after Paracelsus, Van Helmont took the lead in physic; he was a man of most indefatigable industry, and spent fifty years in torturing by every chemical experiment he could devise, the various objects in the animal, vegetable, and mineral kingdoms. He was the first physician who applied alum in uterine hemorrhage, and he acquired a great reputation from the success of the practice.

Sylvius de la Boe, and Otho Tachenius, followed in the track of Van Helmont.

51A prejudice in favour of chemical remedies having been thus introduced, the merited success which attended their operation, and the zeal and perseverance which distinguished the votaries of that science, soon kindled a more general enthusiasm in its favour. It is impossible to reduce into miniature the historical features of these chemical times, so as to bring them within the compass of a lecture: I must therefore rest satisfied with delineating a few of the more prominent outlines. The Galenists, who were in possession of the schools, and whose reasonings were fettered by the strongest predilection for their own doctrines, instantly took the alarm; and the celebrated contest ensued between the Galenical and Chemical sects, which has given such a controversial tone to the writers of the fifteenth and sixteenth centuries. As this revolt from orthodox authority was in a great degree attributed to the mischievous introduction and unmerited success of Antimonial remedies, so were the preparations of this metal denounced with all the virulence of party spirit;^[108] and upon this occasion, in order to support their ground and oppress and persecute their adversaries, the Galenists actually solicited the assistance of secular power; the Supreme Council of Paris accordingly proscribed its use by an edict in 1566, and Besnier was expelled the faculty of medicine in 1609, for having administered it to a patient. In 1637, Antimonial wine was by public authority received into the number of purgatives; and in 1650, a new arrêt rescinded that of 1566, and again restored Antimony to public favour and general reputation; and before we conclude our remarks upon the revolutionary history of this extraordinary metal, it deserves to be remarked, that this very same government that had with such great virulence, and so little justice, persecuted every practitioner who had shewn any predilection for its use, in the year 1720 actually purchased the secret of an antimonial preparation called Panacea Glauberiana, and which has been since known by the title of Kermes Mineral, from a surgeon of the name of La Legerie, who had acquired the secret from a pupil of Glauber. Before this period the invention of Calomel had taken place; this preparation is first mentioned, although very obscurely, by Oswald Crollius, in his Basilica Chemica, in 1608, and in the same year Beguin described it most fully and clearly under the title of Draco Mitigatus, in his Tirocinium Chemicum, which he published in Paris.

Chemistry, at this period^[109] took possession of the schools, and whilst it was gradually grafted into the theory of medicine, it soon became the only guide to its practice, the absurdity of which has been already dwelt upon.

In tracing the march of chemical improvement during the last century, we cannot but be struck with the new and powerful remedies which it has introduced, and the many unimportant and feeble articles which it has dismissed from medical practice.

In the present century, the rapid progress of Chemistry has outstripped 52the anticipations of its most sanguine votaries; and even in the department of vegetable analysis, a correctness has been attained, the very attempt at which had been abandoned by the most illustrious chemists of the former age as hopeless and chimerical; let us for instance only compare the results obtained by the Academicians of Paris, and published by Geoffroy, in their analyses of several hundred plants by the operation of heat, with the elegant and satisfactory researches in this branch of science lately conducted in the same country; whilst the former failed in establishing any distinction between the most inert and the most poisonous plants, the latter have succeeded in detecting, separating, and concentrating several of their most subtile constituents. Opium has been at length compelled to confess its secret source of action, and Ipecacuan to yield its emetic element in a state of perfect purity.

Our Pharmacopœias and Dispensatories^[110] have cautiously kept pace with the scientific progress of the age; and in tracing them from their origin to the present time^[111] it is gratifying to observe the gradual influence of knowledge in reducing the number of their articles—simplifying the composition of their formulæ—and improving the processes for their preparation.^[112] Chemistry has also been the means of establishing the identity of many bodies which were long considered as specifically different; thus an extensive list of animal substances has been discarded, since it is known that they owe their properties to one and the same common principle, as to gelatine, albumen, carbonate of lime, &c.; so again the fixed alkaline salt produced by the incineration of different vegetables, has been found to be potass, from whatever plant it may have been obtained, with the exception of sea plants, and perhaps some of the Tetradynamia, the former of which yield Soda and the latter Ammonia. Previous to the Pharmacopœia of 1745, every vegetable was supposed to yield a salt essentially different, and therefore a number of alkaline preparations were recommended, each bearing the name of the particular plant from which 53it had been procured, as salt of Wormwood—salt of Broom,—Salt of Bean-Stalks, &c.

But, from the very nature and object of a Pharmacopœia, it cannot be supposed to proceed pari passu with the march of chemical science, indeed it would be dangerous that it should, for a chemical theory must receive the seal and stamp of experience before it can become current: a Pharmacopœia however is always an object of abuse, because it is a national work of authority, which is quite a sufficient reason why the ignorant and conceited should question its title to respect, and its claim to utility. “Plures audivi,” says Huxham, “totas blaterantes Pharmacopœias, qui tamen ne intellexerint quidem quid vel ipse pulsus significabat.”

It is very evident, that the greater number of these attacks has not been levelled with any view to elicit truth or to advance science, but to excite public attention, and to provoke unfair discussion for individual and unworthy advantage; their obscure and presumptuous authors vainly hope, that they may gain for their ephemeral writings some share of importance, and for themselves some degree of reputation, if they can only obtain notoriety by provoking a discussion with the College or with some of its responsible members, though such a combat should be sure to terminate in their defeat. Like the Scythian Abaris, who upon being wounded by Apollo, plucked the arrow from his side, and heedless of the pain and disgrace of his wound, exclaimed in triumph that the weapon would in future enable him to deliver Oracles.

It is not to such persons that the observations which are contained in this work are addressed, for with them I am most anxious to avoid a contest, in which, as a worthy Fellow of our College expresses it, “Victory itself must be disgraceful.”

When, however, we are assailed upon every occasion by a gentleman whose talents entitle him to respect, and whose public situation commands notice, I apprehend that a humble individual like myself, may, in the conscientious discharge of a public duty, deliver his sentiments from the chair to which he has been called by his professional brethren, without any risk of compromising the dignity of the College, or of drawing upon himself the charge of an unnecessary and injudicious interference.

The attack to which I chiefly allude, is contained in an historical preface by Mr. Professor Brande, to the Supplement of the Fourth and Fifth Editions of the Encyclopædia Britannica; in which, speaking of the writings of Boerhaave, he says, “The observations which he has made upon the usefulness of Chemistry, and of its necessity to the medical practitioner, may be well enforced at the present day; for, except in the schools of London and Edinburgh, Chemistry, as a branch of education, is either entirely neglected, or, what is perhaps worse, superficially and imperfectly taught; this is especially the case in the English Universities, and the London Pharmacopœia is a record of the want of chemical knowledge, where it is most imperiously required.”

The learned Professor of Oxford, Dr. Kidd, naturally anxious to repel a charge which he considered individually unfair, and to vindicate his University from an aspersion which he felt to be generally unjust, published an animated, but at the same time, a cool and candid defence, to which I have much pleasure in referring you. With respect to the Sister University, my own Alma Mater, I feel that I should be the most ungrateful of her sons, were I, upon this occasion, to omit expressing similar sentiments 54with respect to the course of chemistry, and that of its collateral branches, which are annually delivered in the crouded schools at Cambridge. Is Mr. Brande acquainted with the discipline of our University?—Is he aware that the chemical chair has been successively filled by Bishop Watson—Milner—Wollaston^[113]—and the late lamented Mr. Tennant?—“Master Builders in the Science.” To say that such men have been the lecturers, is surely a sufficient testimony to shew that the science of chemistry heretofore could not “have been neglected, or what perhaps is still worse, imperfectly taught;” and the zeal and ability displayed by the present Professor, ought to have shielded him from any such attack. Is Mr. Brande aware that the eloquent appeal of Bishop Watson from the chair at Cambridge,^[114] on the general importance and utility of chemistry, gave the first impulse to that public taste for this science which so eminently distinguishes our Augustan age, and which has been the means of founding and supporting the Royal, and other Public Institutions in this Metropolis, as well as in the other towns of the British Empire?

I need make no farther remark upon this part of Mr. Brande’s assertion; the sequel, judging from the construction of the sentence, is evidently intended to be understood as a consequence, viz. and therefore “the London Pharmacopœia is a record of the want of chemical knowledge where it is most imperiously required,” because Oxford and Cambridge Physicians were its Editors. Is not this the obvious construction?

It appears from Mr. Brande’s laconic answer to Dr. Young, published in “The Journal of Science and the Arts,” that his objections are those of Mr. Phillips, contained in his experimental examination of the Pharmacopœia; a work which, I confess, appears to me to furnish a testimony of the experimental tact, subtile ingenuity, and caustic style of criticism, which its author so eminently possesses, rather than a proof of any fatal or material inaccuracy in the Pharmacopœia; and I may urge this with greater force and propriety, when it is considered that, at the time of its publication, I was not a Fellow of the College, and therefore had no voice upon the subject of its composition, and consequently must be personally disinterested in its reputation.

I cannot conclude these observations upon Mr. Brande’s attack, without expressing a deep feeling of regret, that a gentleman, whose deserved rank in society, and whose talents and acquirements must entitle him to 55our respect, should have condescended to countenance and encourage that vile and wretched taste of depreciating the value and importance of our most venerable institutions, and of bringing into contempt those acknowledged authorities which must always meet with the approbation of the best, and the sanction and support of the wisest portion of mankind.

And I shall here protest against the prevailing fashion of examining and deciding upon the pretensions of every medicinal compound to our confidence, by a mere chemical investigation of its composition, and of rejecting, as fallacious, every medical testimony which may appear contradictory to the results of the Laboratory; there is no subject in science to which the maxim of Cicero more strictly applies, than to the present case; let the Ultra Chemist therefore cherish it in his remembrance, and profit by its application—“Præstat Naturæ voce doceri, quam Ingenio suo sapere.”

Has not experience fully established the value of many medicinal combinations, which, at the time of their adoption could not receive the sanction of any chemical law? We well remember the opposition, which on this ground was for a long time offered to the introduction of the Anti-hectic Mixture of Dr. Griffith,—the Mistura Ferri Composita of the present Pharmacopœia, and yet subsequent inquiry has confirmed upon scientific principles the justness of our former practical conclusion; for it has been shewn that the chemical decompositions which constituted the objection to its use, are in fact the causes of its utility (see Mist. Ferri,); the explanation, moreover, has thrown additional light upon the theory of other preparations; so true is the observation of the celebrated Morveau, that “We never profit more than by these unexpected results of Experiments, which contradict our Analogies and preconceived Theories.”

Whenever a medicine is found by experience to be effectual, the practitioner should listen with great circumspection to any chemical advice for its correction or improvement. From a mistaken notion of this kind the Extractum Colocynthidis compositum, with a view of making it chemically compatible with Calomel, has been deprived of the Soap which formerly entered into its composition, in consequence of which its solubility in the stomach is considerably modified, its activity is therefore impaired, and its mildness diminished.^[115]

On the other hand, substances may be medically inconsistent, which are chemically compatible, as I shall have frequent opportunities of exemplifying. The stomach has a chemical code of its own, by which the usual affinities of bodies are frequently modified, often suspended, and sometimes entirely subverted; this truth is illustrated in a very striking manner by the interesting experiments of M. Drouard, who found that Copper, swallowed in its metallic state, was not rendered poisonous by meeting with oils, or fatty bodies; nor even with Vinegar, in the digestive organs. Other bodies, on the contrary, seem to possess the same habitudes in the stomach as in the laboratory, and are alike influenced in both situations by the chemical action of various bodies, many examples of which are to be found under the consideration of the influence which solubility exerts upon the medicinal activity of substances; so again, acidity 56in the stomach is neutralized by Alkalies, and if a Carbonate be employed for that purpose, we have a copious disengagement of Carbonic acid gas, which has been frequently very distressing to the patient; lastly, many bodies taken into the stomach undergo decompositions and changes in transitu, independent of any play of chemical affinities from the hidden powers of digestion, some of which we are enabled to appreciate, and they will accordingly form a subject of investigation in the course of the present work.

The powers of the stomach would seem to consist in decomposing the Ingesta, and reducing them into simpler forms, rather than in complicating them, by favouring new combinations.

But every rational physician must feel in its full force, the absurdity of expecting to account for the phænomena of life upon principles deduced from the analogies of inert matter, and we therefore find that the most intelligent physiologists of modern times have been anxious to discourage the attempt, and to deprecate its folly. Sir Gilbert Blane, in his luminous work on Medical Logic, when speaking of the different theories of digestion, tells us that Dr. William Hunter, whose peculiar sagacity and precision of mind detected at a glance the hollowness of such delusive hypotheses, and saw the danger which theorists run in trusting themselves on such slippery ground, expressed himself in his public lectures, with that solidity of judgment combined with facetiousness of expression, which rendered him unparalleled as a public teacher. “Gentlemen,” said he, “Physiologists will have it that the stomach is a mill—others, that it is a fermenting-vat—others again, that it is a stew-pan,—but in my view of the matter, it is neither a mill, a fermenting-vat, nor a stew-pan—but a Stomach, Gentlemen, a Stomach.”

What can illustrate in a more familiar and striking manner the singular powers of Gastric Chemistry, than the fact of the shortness of time in which the aliment becomes acid in depraved digestion? A series of changes is thus produced in a few hours, which would require in the laboratory as many weeks,^[116] while in acute affections of the alimentary canal the functions of the stomach are nearly suspended, and hence under such circumstances, whatever is introduced into this organ remains unchanged, even the nutritious mucilages are not digested.

From what has been said, it is very evident that the mere chemist can have no pretensions to the art of composing or discriminating remedies; whenever he arraigns the scientific propriety of our Prescriptions, in direct contradiction to the deductions of true medical experience,—whenever he forsakes his laboratory for the bed-side, he forfeits all his claims to our respect, and his title to our confidence. It is amusing to see the ridiculous errors into which the chemist falls, when he turns physician; as soon as Seguin found that Peruvian bark contained a peculiar principle that precipitated Tannin, he immediately concluded that this could not be any other than Gelatine, and upon the faith of this blunder, the French, Italian, and German physicians,^[117] gave their patients nothing but Clarified Glue, in intermittent fevers!—But I desist—not however without expressing a hope, 57in which I am sure my medical brethren will concur, that, should Mr. Brande again condescend to favour us with a commentary upon Boerhaave, he will select that passage in his work, where, alluding to the application of Chemistry to Physic, he emphatically exclaims, “Egregia illius Ancilla est, non alia pejor Domina.”

THE INFLUENCE OF SOIL, CULTURE, CLIMATE, AND SEASON.

The facts hitherto collected upon this subject are so scanty and unsatisfactory, that I introduce its consideration in this place, rather with a wish to excite farther enquiry, than with any hope of imparting much additional information.

There can be little doubt, but that Soil, Culture, Climate, and Season,^[118] may very materially influence the active properties of a medicinal plant; while the two latter of these causes may as essentially change the type and character of a disease, and modify the vital susceptibility of the patient; the natives of the south of Europe, for instance, do not bear bleeding, and other modes of depletion, so well as those of the north. This must be admitted to its full extent, or it will be extremely difficult to explain the contradictory and even opposite opinions, and to reconcile the conflicting testimonies of the physicians of different countries, with respect to the efficacy of the same remedy, in similar diseases.

The Influence of Soil may be exemplified by many well known facts; thus, strongly smelling plants lose their odour in a sandy soil, and do not again recover it by transplantation into a richer one; a fact upon which Rozier founded his proposal for the improvement of Rape oil; so again, no management could induce the Ricotia Ægyptiaca to flower, until Linnæus suggested the expediency of mixing clay with the earth in the pot; Assafœtida is one of those plants that vary much according to station and soil, not only in the shape of the leaves, but in the peculiar nauseous quality of the juice which impregnates them, and Dr. Woodville states that it is frequently so modified that the leaves are eaten by goats; Gmelin informs us, on the authority of Steller, that the effects of the Rhododendron have been found to vary materially according to the “solum natale;” for example, that produced in a certain spot has proved uniformly narcotic, that in another, cathartic, while a sense of suffocation has been the only symptom occasioned by a third. Rhubarb, as grown in England, will differ greatly in its purgative qualities, according to the soil in which it may have been cultivated; that produced in a dry gravel being more efficacious than that which is reared in a clayey one. Dr. Carter, in his account of the “Principal Hospitals of France, Italy, and Switzerland,” tells us that at Nice, the Digitalis is commonly given in doses of a scruple in powder, or in that of half an ounce of the infusion made according to the London Pharmacopœia, every hour, and without any sensible effect; this fact he explains by stating that the Digitalis, in the neighbourhood of Nice, is much smaller, and is probably less powerful than the same plant as it grows in England.

58Climate also produces a powerful impression upon vegetable and animal life. It is probable that in southern countries some vegetables enjoy more energetic properties than in northern climes. The history of opium immediately countenances such an opinion; thus Egypt produces a stronger opium than any of the countries on the north side of the Mediterranean,—France, than England or Germany;—and Languedoc, than the northern parts of France;—while Smyrna, Natolia, Aleppo, and Apulia, furnish a juice far more narcotic than Languedoc: so again, Senna by transplantation from Arabia into the south of France (Provence) assumes a marked change in its physiognomy and virtues, its leaves are more obtuse, and its taste less bitter and nauseous than the pointed leaved variety, while its effects will be found to be less purgative. Cruciform plants degenerate within the tropics, but acquire increased energies, as Antiscorbutics, in cold regions; the Menthæ have not so penetrating an essential oil in the south of Europe as in England and in the north of France. The relative proportions of gluten vary in the wheat of different countries, and as in the south of Europe, its quantity greatly predominates over the other principles, we at once discover the cause that gives such excellence to the Maccaroni of Italy. Many species of plants secrete juices in warmer regions, which are unknown in their œconomy, in colder climates; thus the Ash yields Manna in Calabria, but loses that faculty as it advances towards the north. The influence of climate, in its relations to moisture and dryness, upon vegetable productions, is also worthy of investigation; in wet and cold seasons, our herbage is far less nutritive to cattle, and we accordingly find that they are constantly grazing, in order to compensate by quantity, for what is deficient in quality, whereas in dry seasons, a larger proportion of their time is consumed in rumination; the same causes, however, that diminish the nutritive powers of plants, frequently increase the energy of those principles upon which their medicinal value depends: it is obvious that many herbs are more rank and virulent in wet and gloomy seasons: this would appear to be a wise and provident law, in order to apportion the natural condiment of the vegetable, to the deteriorated state of its nutritive elements, when the digestive organs must require more than the ordinary stimulus for the due exercise of their functions. It is hardly necessary to observe that plants, which in temperate climates are merely shrubs, have been developed into trees, by the hot and humid plains of Africa and Asia; while in the arid deserts of Nubia or in the frigid plains of Siberia, vegetable life is confined to stunted shrubs and humble mosses: cold also suppresses the colour of flowers, and indeed even that of the leaves, as is witnessed in the Cyclamen, Amaranthus, and Ranunculus of Lapland and Siberia. But climate not only modifies the powers of a remedy by influencing its structure and composition, but it renders it more or less active, by increasing or diminishing the susceptibility of the body to its impression; can a more striking proof of this fact be adduced than the well known effects of perfumes at Rome? The inhabitants are unable to sustain the strong scent of flowers in that climate, without experiencing a sensation highly oppressive, and which in some cases is even succeeded by syncope,^[119] and thus realising the well known line of the poet,

As I have been favoured with some very interesting observations upon this subject by Dr. Richard Harrison, who resided for a considerable time in Italy, and was thus enabled to institute a satisfactory inquiry into this curious subject, I feel no hesitation in introducing a quotation from his letter to my readers.—“You ask me what experience I have had on the subject of climate, as affecting the powers and operation of remedies; I have no difficulty in asserting that Narcotics act with greater force even in smaller doses at Naples, where I had the advantages of much experience, than in England. I might adduce as an example the Extract of Hyoscyamus, which, when given to the extent of three grains thrice a day, produced in two patients a temporary amaurosis, which disappeared and again recurred on the alternate suspension and administration of this medicine; and it deserves particular notice that these very patients had been in the habit of taking similar doses of the same remedy in England, without any unpleasant result. Now that this depended upon an increased susceptibility of the patient, in the warmer climate, rather than an increased power in the remedy, is unquestionable, since the extract which was administered in Italy had been procured from London; indeed a high state of nervous irritation is the prevalent disorder of Naples. I treated several cases of Epilepsy in Italy with the nitrate of silver, and with complete success, while in England I certainly have not met with the same successful results. During my residence at Naples, I spent some time in the island of Ischia, so celebrated all over the continent for its baths; many of the patients who were then trying their efficacy, had been attacked by Paralysis, Apoplexy, and almost every degree of loss of mental and muscular power, and among them I certainly witnessed what with propriety might be denominated a genuine case of Nervous Apoplexy. These complaints I was generally able to trace to the abuse of Mercury, whence we may, I think, very fairly conclude that this metal is more active in its effects in that, than in our own country. Before I quit this subject, I ought to mention that the doses of medicines, as seen in the prescriptions and works of English Physicians, excite universal astonishment among the faculty of Italy. In fact, as I have just stated, the human constitution in this part of the continent is certainly more susceptible of nervous impression than in England: it is perfectly true that flowers or perfumes in a chamber, will frequently produce syncope in persons apparently strong and healthy, and the fact is so universally admitted, that the Italians avoid them with the greatest caution.” On the other hand, it appears equally evident that some remedies succeed in cold climates which produce little or no benefit in warmer latitudes. Soon after the publication of the first edition of my Pharmacologia, I received a letter from Dr. Halliday of Moscow, upon the subject of the “Eau Medicinale,” and as it offers a striking proof of the efficacy of the Rhododendron Chrysanthum in curing the rheumatism of the North, whilst in this country the plant has been repeatedly tried without any signal proof of success, I shall here subjoin an extract from the letter of my correspondent: “In reading your account of the ‘Eau Medicinale,’ I perceive that, upon the authority of Mr. James Moore, you state it to be a preparation of the White Hellebore; may I be allowed to suggest the probability of its being made from the leaves of the Rhododendron Chrysanthum? for so far as I can learn, 60the effects of the French medicine are precisely those which are experienced from an infusion of the above plant, which the Siberians and Russians regard as an infallible specific in the cure of chronic rheumatism and gout, and from which I myself, as well as other physicians in Russia, have witnessed the most desirable and decided effects, whenever we had it in our power to administer the remedy with confidence and courage. We have seldom given it in any other form or dose than that adopted by the Siberians themselves, which is to infuse in a warm place, generally near a furnace and during the night, two drachms of the fresh leaves in about twelve ounces of boiling water, taking care that the liquid never boils. This dose is to be taken in the morning upon an empty stomach, and during its nauseating operation, which generally commences within a quarter of an hour after it has been swallowed, neither solids nor liquids of any description are allowed; after an interval of three or four hours, I have seen the patient obtain a copious and black fœtid stool, and get up free from pain. Should it happen that the patient does not recover from the first dose, another is administered on the succeeding day, and I have known it to be taken for three days in succession, when the severest fits of gout have been removed.^[120] Is it not then probable that some cunning Frenchman has availed himself of this Siberian specific, and concentrated it in such a form, as to defy all the learned to find it out?”

Dr. Halliday adds, “The Siberians denominate the leaves of this plant, when infused in water, Intoxicating Tea; and a weaker infusion is in daily use, especially for treating their neighbours, just as the Europeans do with tea from China.”

Before we quit the consideration of Climate, as being capable of influencing the activity of a remedy, the important fact should not be overlooked, that in India, and other colonies of similar temperature, Mercurial Medicines, in order to produce their beneficial effects, require to be administered to an extent which would prove destructive to the inhabitants of this island.

But of all the circumstances that produce the greatest change in the aspect as well as in the virtues of the vegetable creation, is Cultivation, which may either destroy the medicinal properties of a plant, or raise in it new and most valuable qualities: cultivation converts single into double flowers, by developing the stamens into petals, a change which in many cases destroys their efficacy, as in the camomile, Anthemis Nobilis; for, since all the virtues of this flower reside in the disc florets, it is of course greatly deteriorated by being converted into the double-flowered variety; by the operation of grafting extraordinary changes may also be produced; Olivier, in his travels, informs us that a soft Mastiche, having all the qualities of that resin, except its consistence, which is that of turpentine, is procured by engrafting the Lentisk on the Chian Turpentine tree.

Buffon states that our wheat is a factitious production raised to its present condition by the art of agriculture. M. Virey^[121] observes, that by 61suppressing the growth of one part of a plant we may respectively give rise to an increased developement in others; thus are some vegetables rendered eunuchs, or are deprived of seeds by obliteration, and only propagate themselves by slips; such a condition is frequently produced by culture, continued through a long succession of generations; this is the case with the Banana, Sugar Cane, and other fruits that have carefully been made to deviate for a long series of years from their original types, and having been continually transplanted by slips, suckers, or roots, at length only propagate themselves in this way, whereby the roots, as those of the common potatoe, become inordinately developed, drawing to themselves the succulence and nutrition originally possessed by the berries. It seems probable that we may thus have lost many vegetable species; the Tuberes of Pliny, for example, are supposed by Mr. Andrew Knight to have been intermediate productions, formed during the advancement of the Almond to the Peach, or in other words that they were swollen almonds or imperfect peaches; if this conjecture be admitted, it will explain the fact stated by Columella, that the peach possessed deleterious qualities when it was first introduced from Persia into the Roman Empire. If there be any who feel sceptical upon the subject of such metamorphoses, let him visit the fairy bowers of Horticulture, and he will there perceive that her magic wand has not only converted the tough, coriaceous covering of the Almond into the soft and melting flesh of the Peach, but that by her spells, the sour Sloe has ripened into the delicious Plum, and the austere Crab of our woods into the Golden Pippin; that this again has been made to sport in endless variety, emulating in beauty of form and colour, in exuberance of fertility and in richness of flavour, the rarer productions of warmer regions, and more propitious climates! In our culinary vegetables the same progressive amelioration and advancement may be traced; thus has the acrid and disagreeable Apium graveolens been changed into delicious Celery, and the common Colewort, by culture continued through many ages, appears under the improved and more useful forms of Cabbage, Savoy, and Cauliflower. It has been already observed that the alimentary and medicinal virtues are frequently in opposition to each other, and that while cultivation improves the former, it equally diminishes the latter; I shall have occasion to offer some additional facts upon this curious subject, under the consideration of Bitter Extractive; see Note on this Extract, in the article “Tonics.”

THE IGNORANT PREPARATION AND FRAUDULENT ADULTERATION OF MEDICINES.

The circumstances comprehended under this head certainly deserve to be ranked amongst the more powerful causes, which have operated in affecting the reputation of many medicinal substances. The Peruvian Bark fell into total discredit in the year 1779, from its inability to cure the ague; and it was afterwards discovered to have been adulterated with bark of an inferior species; indeed Sydenham speaks of the adulteration of this substance before the year 1678; he tells us that he had never used to exceed two drachms of Cinchona in the cure of any intermittent, but that of late the drug was so inert, rotten, and adulterated, it became necessary to increase its dose to one, two, or three ounces. The subject is copious and full of importance, and I have taken considerable pains to collect very 62fully, the various modes in which our remedies are thus deprived of their most valuable properties, and to suggest the best tests by which such frauds may be discovered. Very few practitioners have an idea of the alarming extent to which this nefarious practice is carried, or of the systematic manner in which it is conducted: there can be no doubt but that the sophistication of medicines has been practised in degree in all ages,^[122] but the refinements of chemistry have enabled the manufacturers of the present day, not only to execute these frauds with greater address, but unfortunately, at the same time, to vend them with less chance of detection. It will be scarcely credited, when I affirm that many hundred persons are supported in this metropolis by the art of adulterating drugs, besides a number of women and children who find ample employment and excellent profit in counterfeiting Cochineal with coloured dough, Isinglass with pieces of bladder and the dried skin of soles, and by filling up with powdered Sassafras the holes which are bored in spice and nutmegs, for the purpose of plundering their essential oils.

THE UNSEASONABLE COLLECTION OF VEGETABLE REMEDIES.

Vegetable physiology has demonstrated, that during the progress of vegetation most remarkable changes occur in succession, in the chemical composition, as well as in the sensible qualities of a plant; time will not allow me to be prodigal of examples, take therefore one which is familiar and striking,—the aromatic and spicy qualities of the unexpanded flowers of the Caryophyllus Aromaticus (Cloves) are well known to every body, but if the flower-bud be fully developed it loses these properties altogether, and the fruit of the tree is not in the least degree aromatic; so the berries of Pimento, when they come to full maturity, lose their aromatic warmth and acquire a flavour very analogous to that of Juniper. The Colchicum autumnale may be cited as another example in which the medicinal properties of the vegetable are entirely changed during the natural progress of its developement. See also Inspissated Juices, under the article Extract.

THE OBSCURITY WHICH HAS ATTENDED THE OPERATION OF COMPOUND MEDICINES.

It is evident that the fallacies to which our observations and experience are liable with respect to the efficacy of certain bodies, as remedies, must be necessarily multiplied when such bodies are exhibited in a state of complicated combination, since it must be always difficult, and often impossible, to ascertain to which ingredient the effects produced ought to be attributed.

How many frivolous substances have from this cause alone gained a share of credit, which belonged exclusively to the medicines with which 63they happened to be accidentally administered?^[123] Numerous are the examples which I might adduce in proof of this assertion; the history of Bezoar^[124] would in itself furnish a mass of striking evidence, indeed the reputation of this absurd substance was maintained much longer than it otherwise would have been, by its exhibition having been frequently accompanied with that of more active articles. Monardes, for instance, extols the efficacy of the Bezoar as a vermifuge, but he states that it should be mixed with the seeds of Wormwood. Besides, in the exuberance of mixture, certain re-actions and important changes are mutually produced, by which the identity of the original ingredients is destroyed; but this subject will be introduced for discussion in the first part of the Pharmacologia.

The practice of mixing together different medicinal substances, so as to form one remedy, may boast of very ancient origin, for most of the prescriptions which have descended from the Greek physicians are of this description; the uncertain and vague results of such a practice appear also to have been early felt, and often condemned, and even Erasistratus declaimed with great warmth against the complicated medicines which were administered in his time; the greater number of these compositions present a mass of incongruous materials, put together without any apparent order or intention; indeed it would almost appear as if they regarded a medical formula as a problem in Permutation, the only object of which was to discover and assign the number of changes that can be made in any given number of things, all different from each other.

At the same time it must in justice be allowed, that some of the earlier physicians entertained just notions with regard to the use and abuse of combination, although their knowledge of the subject was of course extremely limited and imperfect.

Oribasius^[125] recommends in high terms certain combinations of Evacuant and Roborant medicines, and the remarks of Alexander Trallianus on a remedy which he exhibited in paralysis, serve to shew that he was well acquainted with the fact, that certain substances lose their efficacy 64when they stimulate the bowels to excess, for he cautions us against adding a greater proportion of Scammony to it; many, he observes, think that by so doing, they increase the force of the medicine, whereas in fact they make it useless, by carrying it immediately through the bowels, instead of suffering it to remain and be conveyed to the remote parts.

In modern Europe, the same attachment to luxuriancy of composition has been transmitted to our own times: there are several prescriptions of Huxham extant, which contain more than four hundred ingredients. I have already observed that all extravagant systems tend, in the course of time, to introduce practices of an opposite kind; this truth finds another powerful illustration in the history of medicinal combination, and it becomes a serious question, which it will be my duty to discuss, whether the disgust so justly excited by the poly-pharmacy of our predecessors, may not have induced the physician of the present day to carry his ideas of simplicity too far, so as to neglect and lose the advantages which in many cases beyond all doubt may be obtained by scientific combinations. “To those,” says Sir A. Crichton, “who think that the Science of Medicine is improved by an affected simplicity in prescribing, I would remark, that modern pharmacopœias are shorn so much of old and approved receipts,^[126] on account of their being extraordinary compounds, so as to be almost useless in some cases.”

In the year 1799, Dr. Fordyce, in a valuable paper published in the second volume of the Transactions of the Medical Society, investigated this subject with much perspicuity and success: unfortunately, however, this memoir terminates with the investigation of similar remedies, that is to say, of those which produce upon the body similar effects, and he is entirely silent upon the advantages which may be obtained by the combination of those medicines which possess different, or even opposite qualities; it must be also remembered that at the time this memoir was composed by its eminent author, Chemistry had scarcely extended its illuminating rays into the recesses of physic. Under such circumstances, I am induced to undertake the arduous task of inquiring into the several relations in which each article of a compound formula may be advantageously situated with respect to the others; and I am farther encouraged in this investigation, by a conviction of its practical importance, as well as by feeling that it has hitherto never received the share of attention which it merits. “I think,” says Dr. Powell, “it may be asserted, without fear of contradiction, that no medicine compounded of five or six simple articles, has hitherto had its powers examined in a rational manner.” If this attempt should be the means of directing the attention of future practitioners to the subject, and thereby of rendering the Art of Composition more efficient, by placing it upon the permanent basis of science, I shall feel that I have profitably devoted my time and attention to the most useful of all medical subjects. “Res est maximi momenti in arte medendi, cum, Formula in se considerata, possit esse profecto mortis vel vitæ sententia.”

“Medicos tandem tædet et pudet, diutius garrire de Remediis, Specificis, et Alexipharmicis, et cæteris, nisi eorum naturam et modum quo prosint, quodammodo ostendere et explanare possint.”

Medicinal Substances are those bodies, which, by due administration, are capable of producing certain changes in the condition of the living system, whereby its morbid actions may be entirely removed, or advantageously controlled.

In adopting this definition we intentionally exclude those alimentary substances which are more immediately subservient to the support of life, and to the repair of that diurnal waste, which the exercise of its functions so inevitably occasions.

It has been generally supposed, that substances whose application does not produce any sensible action upon the healthy system, cannot possess medicinal energy; and, on the contrary, that those bodies which occasion an apparent effect in health, must necessarily prove active in the cure or palliation of disease. Under certain limitations we may perhaps venture to assent to this general proposition; but it cannot be too forcibly or too frequently impressed upon the mind of the medical practitioner, that Medicines are frequently but relative agents, producing their effects in reference only to the state of the living frame; we must therefore concur with Sir Gilbert Blane in stating, that the virtues of Medicines cannot be fairly essayed, nor beneficially ascertained, by trying their effects on sound subjects, because that particular morbid condition does not exist which they may be exclusively calculated to remove;^[127] thus in certain states of debility, Tonics may excite the system when languid, by their sympathetic influence upon the primæ viæ, while in a robust condition of the body, the effects of the same agents may be wholly inappreciable.

The Modus Operandi of remedies, or the general principle upon which they effect salutary changes in the morbid states of the body, is involved in considerable obscurity, and has given rise to much ingenious 68speculation and scientific controversy. It would seem that the immediate impression of a remedy may depend upon mechanical, chemical, or vital agencies; and that the sanative impulse thus occasioned may either be Absolute, or Relative;—Primary, or Secondary;—Local, or General;—Direct, or Sympathetic;—Permanent, or Transient;—thus certain purgatives will occasion intestinal excretions in every condition of the body, and may therefore be justly considered as absolute agents; while diuretics, since they generally require for their success, a certain state of the living system, may with equal truth be denominated relative in their operation. That the obvious effect of a remedy may either depend upon its Primary, or upon its Secondary and incidental operation, will at once be apparent by inspecting the diagram which exhibits the classification of diuretic medicines; the same scheme will also shew that remedies may be local or general in their effects, and may excite an action in distant organs, either by entering the circulating mass, and being thus brought into contact with their textures;—by occasioning an impulse conveyed through the nervous system,—or by exciting a local impression upon the stomach and primæ viæ, and thus arousing their energies through the mysterious medium of sympathetic^[128] communication.

That certain bodies are capable of evading the assimilating functions, and of entering, unchanged, into the circulating current, either through the branches of the thoracic duct, or of the vena portarum, is a fact which admits of chemical demonstration; many of the alkaline salts are thus conveyed to the kidneys, and being excreted from the blood by its vessels, are to be easily detected in the urine by appropriate reagents; I have made many experiments upon this subject, and am prepared to state some results which may perhaps explain the occasional value of such bodies as medicines. Some essential oils, particular bitter principles,^[129] and certain colouring matter,^[130] seem also capable of passing the barriers of digestion, and of circulating to the remote parts of the body; Mercury, and several of the other metals, would likewise appear, under certain circumstances, to possess a similar privilege, and the former to be able moreover to facilitate the absorption of other bodies with which it may be associated, as I shall hereafter more fully exemplify.

In some instances, the medicinal body undergoes a partial decomposition by the digestive organs, in transitu, by which some of its constituents escape into the circulation, while the others are completely digested, and converted into chyle; this occurs with saline compounds into which vegetable acids enter as constituents. See Potassæ Acetas. It is also stated 69in the history of Diluents, that there is reason to believe that Water may under particular circumstances suffer decomposition, and transfer its elements for the formation of new compounds, furnishing oxygen to some, and hydrogen to others. There is likewise reason to suppose, that in particular conditions of the digestive functions, a remedy may be at once rendered inert by its entire decomposition.^[131]

That an impression made upon the stomach by a medicinal agent, should be the means of exciting an action in the distant parts of the machine, will not appear extraordinary when we consider how universal a sympathy and control this central organ exercises over every function of the body; imbued with exquisite and diversified sensibilities,—subjected to the first and coarsest impressions of our various ingesta,—stretched occasionally to an enormous extent by the unrestricted indulgence of appetite,—disturbed by the passions,—exhausted by volition, and debilitated by intense thinking; in short, assailed by numerous foes from without, and harassed by various revolutions from within, can we feel surprised that the aberrations of this viscus should give origin to the greater number of maladies with which we are afflicted, or that those medicinal applications should be effective that are directed for their cure, through the medium of its sympathies?

A dose of Ipecacuan, by exciting the stomach, will abate both the force and velocity of the heart in its vital motion, and affect the whole series of blood vessels, from their origin to their most minute ramifications, as is evinced by the pallor of the skin under its operation, as well as by its efficacy in arresting hemorrhage; so the brain, when disordered by vertigo, frequently derives instantaneous relief from the administration of a tea-spoonful of æther in a glass of water. The stomach however is not in every case the medium of sympathy; a substance may excite a powerful impression upon a distant part, by the instrumentality of the nerves, without any concurrence of the stomach; thus, the Belladonna, by coming in contact with the Tunica Conjunctiva of the eye, will occasion immediate dilatation of the Iris, although no other part of the system is in the slightest degree affected.

But there is yet another mode by which remedies may be made to exert a sanative effect upon particular organs of the body, through the medium of what Mr. Hunter called contiguous sympathy, and whose existence 70appears to depend upon the mere proximity and contiguity of parts, without any relation to the distribution of the nerves; thus it is, that relief is afforded to a deep-seated inflammation, by scarifying the nearest external surface; while we know from long experience that the thoracic or abdominal viscera, when similarly affected, receive corresponding relief from the same topical use of bleeding, blistering, or fomenting.

With respect to the Modus Operandi of medicines the following classification may be established.

And it is important to observe, that these are frequently antagonist operations, and consequently, that remedies, although they should occasion the same apparent effects, unless they act through the same medium, are not SIMILAR agents, but on the contrary, are generally medicinally incompatible with each other; for an illustration of this truth, the practitioner may refer to the observations which I have offered under the history of diuretics.

The difficulty of justly appreciating these phenomena, in every instance, has furnished a powerful objection against the validity of any classification of medicinal substances which is founded on their supposed modes of operation; and it must be acknowledged that, if we are unable to assign to remedies their primary action, or to distinguish this from their more obvious, though perhaps secondary effects, we shall frequently be 71compelled to place similar medicines under opposite heads, and to include those of very dissimilar characters under the same artificial division; an error which has contributed more generally to embarrass and misguide our practice than any other therapeutical fallacy, and it was the conviction of this truth which induced me to introduce the present chapter, and to impress the importance of its subject upon the attention of my practical readers.

It is probable that, in philosophical strictness, no two medicines in our Materia Medica are perfectly similar, although they recede from each other by such insensible shades of gradation that we may with practical advantage admit their parallelism; at the same time, it must be ever kept in remembrance, that those Medicines only are practically similar, whose operations have been found by experience to continue similar under every condition of the human body; and which, moreover, owe such similarity to modes of operation which are compatible with each other, and consonant with the general indications of cure.

The importance of admitting this proposition will be frequently illustrated in the sequel; and it may be observed in this place, that every classification in which it is not recognised as a leading principle, must be as imperfect in its execution, as it will be unjust and erroneous in its views.

Before I proceed to any farther discussion upon the present subject, it will be necessary to offer a synoptical view of an arrangement of medicinal bodies founded upon the basis of their operations, in order that I may be better enabled to illustrate the observations which it is my intention to introduce: for this purpose I shall present the reader with three different classifications of this kind; the first being that proposed by Dr. Cullen,^[134] and which is now admitted to rest on principles nearly altogether false, but the investigation of which will afford many useful lessons of practical importance; the second classification is by Dr. Young;^[135] and the third is that proposed by Dr. Murray,^[136] which, from its simplicity and strict conformity with the views I intend to offer, will be adopted as being the most eligible for the occasion.

With respect to the classification of Dr. Cullen, we may commence our objections by stating, that the very basis upon which it rests is a mere gratuitous assumption, viz. that certain medicines act on the fluids of the body. With the exception of a very few substances, it is now generally admitted that medicines produce their effects by acting on the living materials of which our organs are composed, and not by modifying the specific gravity, or chemical composition, of the fluids which they may happen to evacuate. The origin of this latter opinion is to be traced to the exploded notions of the humoral pathologists, and to the exclusive doctrine of the earlier chemists; for as the former recognised a depraved condition of the fluids as the source of every disease, so did the latter imagine that every remedy operated by producing a chemical change upon its composition; and the remedial value of a medicinal substance was estimated by its effects upon inert matter. Thus were experiments made with different substances upon the blood, and other fluids of the body, in order to deduce, from the results, the nature and extent of their powers as agents upon the living frame; for instance, the spirit and salt of hartshorn, as they were found to render the blood more fluid, when added to it, out of the body, 75were indiscriminately administered in almost every complaint, with a view to dissolve that “lentor of the fluids” which was regarded as the more general source of disease. For similar reasons, a tribe of medicines were introduced into practice under the title of Antiseptics, for the prevention of a process which very probably never takes place in the living body: the powers of these supposed agents were, as usual, inferred from their effects in resisting and preventing the putrefaction of dead matter.

Nor is the distinction assumed by Dr. Cullen, between the action of remedies on the Simple and Living solids less hypothetical. Tonics and astringents may certainly exert a beneficial effect upon the animal fibre, but not by any immediate action on its materials, but through the agency of its living principle.—“Medicamentum non agit in cadaver.”

The classification of Dr. Young, although it presents many points of interest and value, is not altogether free from objection; his classes in some instances are perhaps unnecessarily sub-divided, without a sufficient regard to the primary and secondary operations of the substances which they include. The arrangement of Murray has been adopted in the present inquiry, not as being less objectionable, in a general point of view, but as one which from its simplicity, is better calculated, as a frame-work, if I may so express myself, for the display of those particular facts, the knowledge of which I consider essential for the successful administration of medicinal agents, and for the full comprehension of those practical doctrines which it is the exclusive object of this work to inculcate.

Dr. Murray observes that, in this arrangement, he places in the first division those substances which exert a GENERAL STIMULANT operation on the system. Of this there are two sub-divisions, the Diffusible and the Permanent; the former including the class of Narcotics, with which may be associated, as not very remote in their operation, the class of Antispasmodics; the latter comprising two classes, viz. Tonics and Astringents. Through these there is a gradual transition from the most highly diffusible stimulant, to those most slow and durable in their action.

A second division comprehends Local Stimulants, those, the action of which is determined to particular parts of the system. Such are the classes of Emetics, Cathartics, Emmenagogues, Diuretics, Diaphoretics, Expectorants, and Sialogogues; with which may be associated the classes of Errhines and of Epispastics, founded on direct local application.

The remaining classes include substances which do not operate according to laws peculiar to the living system. To one division may be referred those, whose effects depend on the Chemical changes they produce in the fluids or solids; the classes which may be established on this principle are Refrigerants, Antacids, Lithonthriptics, and Escharotics. To another division belong those, the operation of which is purely Mechanical, as Anthelmintics, Demulcents, Diluents, Emollients, and certain Laxatives.

Under the above classes, says Dr. Murray,^[137] may be comprehended all those substances which are capable of producing salutary changes in the human system, and which are used as remedies. I have stated my reasons for adopting this as a general basis of classification, although I shall deviate very considerably in the subordinate divisions of the plan, in the hope of establishing some distinctions that may tend to practical utility.

The four classes comprehended under this first division, are Narcotics, Antispasmodics, Tonics, and Astringents.

Although these remedies differ very essentially in the degree and permanence of their action, as well as in the character of their apparent effects, yet, as it is conceived that their primary operation is stimulant, they are considered as possessing sufficient general similitude to sanction their arrangement under one comprehensive division.

NARCOTICS.

Substances which, in a moderate dose, occasion a temporary increase of the actions of the nervous and vascular systems, but which is followed by a greater depression of the vital powers than is commensurate with the degree of previous excitement, and which is generally followed by sleep.

The relative intensity of these primary and secondary effects varies in the different narcotics,^[138] and even in the same narcotic in different doses; in some cases, especially if the quantity administered be considerable, the symptoms of diminished sense and action follow so immediately, that the previous stage of increased action is very obscure, or not in the least perceptible, while in other cases, the operation of the substance is more particularly directed towards the heart and arteries, and syncope succeeds its exhibition. These facts have led many physiologists to deny the stimulant nature of these bodies, and to consider their primary operation as one of a depressing kind, whence they have bestowed upon them the name of Sedatives; in referring to the classification of Cullen and Young, we shall find that the arrangement of these substances has been directed in strict conformity with such a view of the subject; but it may be asked, how the increased excitement and exhilaration which so obviously follow the use of these bodies, in small doses, can be reconciled with that theory which considers them as absolutely and primarily sedative? In order to combat an argument so fatal to his hypothesis, Dr. Cullen summons to his aid the potent intercession of his tutelar deity, the Vis Medicatrix, a power which he supposes to preside over our living body, and with anxious vigilance, to resist the invasion of every thing that is noxious, or hostile to its health and well being; with such assistance it was not difficult to explain any paradox in physiology, and the anomalies attending the agency of narcotic medicines were accordingly, in the school of Cullen, easily reconciled with the views of a favourite theory. He supposed that whenever a sedative was applied in a moderate dose, the Vis Medicatrix took the alarm, and excited all the powers of the system, in order to throw off the noxious application, and that thus indirectly arose those peculiar symptoms of increased action; but when the dose was more considerable, he contended that the preserving power 77of the system was silenced, and unable to offer any salutary resistance, and consequently that universal depression immediately followed; but there is no direct evidence in support of the existence of such a power, and still less of its influence upon such occasions; it is far more philosophical to refer the operation of narcotics to a peculiar stimulating power, remarkable for the extreme rapidity with which it exhausts the energy of the nervous system. No one will deny the stimulating powers of alcohol, and yet a very large draught of this liquor will occasion extreme exhaustion without the occurrence of any signs of previous excitement; nor will any one be disposed to question the depressing influence of opium, and yet small doses have enkindled excitement and sustained the powers of life, under circumstances of extreme and alarming exhaustion.^[139]

From the celerity with which narcotics produce their effects, it is reasonable to suppose that they act upon the nervous system through the sympathetic relations of the stomach, although in some instances it is highly probable that these bodies are actually absorbed into the circulation; I am inclined to think that this occurs with opium, as death is accelerated in cases of persons poisoned by it, by the adoption of those measures which are best calculated to promote its absorption: (see Opium.) A still more striking proof is furnished by the fact of opium, when externally applied to ulcers, producing all its constitutional effects, such as costiveness, head-ache, nausea, &c. Whether the effects of spirituous potations are to be attributed to the introduction of alcohol into the blood, or to the sympathies existing between the stomach and brain, is still a question of doubt. Dr. Cooke^[140] relates a case, on the authority of Sir A. Carlisle, of a person who was brought dead into the Westminster Hospital, in consequence of having drank a quart of gin for a wager, and that upon examination, a considerable quantity of a limpid fluid was found within the lateral ventricles of the brain, distinctly impregnated with gin. I very well remember the case, for it occurred during the period that I held the situation of Physician to that hospital, but it is very doubtful whether such an absorption occurs under ordinary circumstances. We well know the facility with which certain odorous bodies enter the circulation, and are developed in distant organs; it is therefore very possible that the apparent odour of the gin, which has been sometimes recognized in the secretions, may depend upon the presence of the flavouring ingredients, independent of the alcohol?

At one period, substances supposed to possess narcotic virtues were placed about the bed to obviate watchfulness; the plant Anethum, or Dill, was very commonly suspended over the head for such a purpose, while in modern times the Hop has been introduced into the pillow.

In concluding the history of Narcotics, it may be observed, that there is, perhaps, no class of medicinal bodies, the individuals of which are less disposed to bend and conform to an artificial arrangement; each would seem to have its own particular mode of operation, and to affect sensibility in its own peculiar manner; and hence the practitioner will often find that, after the failure of one narcotic, the administration of another will induce sleep.

Substances which have the power of allaying the inordinate action of muscular structures, and of assuaging pain, without occasioning that state of insensibility which characterises the operation of narcotics.

There are certain medicinal bodies which would appear to exert a specific control over spasmodic action, from whatever cause it may have originated, such are Assafœtida, Galbanum, Musk, Castor, Ammonia, Valerian, &c. To such remedies the term antispasmodic more exclusively belongs, but in a more general view of the subject we must admit that this class branches, by indefinable gradations, into narcotics and tonics; for since spasm may be connected with the most opposite states of the body, it is very evident that many of the individuals included in the class of antispasmodics, can only be relative agents: spasm, for instance, may arise from excessive irritability, as from teething, wounds, worms, &c. in which case a narcotic would prove beneficial; or it may depend upon a state of general debility, the proper remedy for which would be the administration of an Aromatic Stimulant, or the assiduous exhibition of some permanent tonic.

TONICS.

Substances, whose continued administration gives strength and vigour to the body.

It is very justly admitted, that a state of permanent tension in the fibres of the body is necessary for the existence of life, and that any undue departure from such a condition is followed by debility. Thus, Sir Gilbert Blane observes, that no muscle, whether voluntary or involuntary, can act unless its fibres are previously in such a state, that if divided they would shrink by their own resiliency, leaving an interval between the cut extremities; the same may be said of the vascular system in all its ramifications, in order to give play to their contraction in grasping and propelling their contained fluids. It appears that there are certain medicinal bodies that have the power of affecting this state of tension, and when their effects contribute to its restoration, they are properly denominated Tonics. We are not, however, to consider them as producing such a change by any mechanical operation upon the matter of which the fibre is composed, but by a direct action upon its living principle; it seems probable that certain poisons may thus produce sudden death by their agency on the vital principle, by which the tension of the heart and whole arterial system is immediately relaxed. In this point of view, Tonics, like the other remedies which we have described, may be relative or absolute in their operation. Venesection, purgation, or whatever will, under certain conditions of the body, occasion a salutary change in its vital powers, may produce a corresponding alteration in the tension of its fibres, and consequently fall under the denomination of a tonic remedy: but independent of the state of the body, there would seem to be certain substances that act as specific stimuli upon the living fibre, and are in certain cases indispensable for the maintenance of its healthy tone; such are vegetable bitters, which produce a powerful effect upon the digestive organs, and by nervous sympathy, 79upon the rest of the system. Bitter Extractive,^[141] seems to be as essential to the digestion of herbivorous, as salt is to that of carnivorous animals; it acts as a natural stimulant, for it has been shewn by a variety of experiments that it passes through the body without suffering any diminution in its quantity, or change in its nature. No cattle will thrive upon grasses which do not contain a portion of this vegetable principle; this fact has been most satisfactorily proved by the late researches of Mr. Sinclair, gardener to the Duke of Bedford, which are recorded in that magnificent work, the “Hortus Gramineus Woburnensis.” They shew, that if sheep are fed on Yellow Turnips, which contain little or no bitter principle, they instinctively seek for, and greedily devour any provender which may contain it, and if they cannot so obtain it they become diseased and die. We are ourselves conscious of the invigorating effects of slight bitters upon our stomach; and their presence in malt liquors not only tends to diminish the noxious effects of such potations, by counteracting the indirect debility which they are liable to occasion, but even to render them, when taken in moderation, promoters of digestion. The custom of infusing bitter herbs in vinous drinks is very ancient and universal; the Poculum Absinthiatum was regarded in remote ages as a wholesome beverage, and the Wormwood was supposed to act as an antidote against drunkenness. The Swiss peasant cheers himself amidst the frigid solitude of his glaciers, with a spirit distilled from Gentian, the extreme bitterness of which is relished with a glee that is quite unintelligible to a more cultivated taste. With regard to the natural use of Bitter Extractive, it may be laid down as a truth, that it stimulates the stomach,—corrects putrefying and unwholesome nutriment,—promotes tardy digestion,—increases the nutritive powers of those vegetable substances to which it is united,—and furnishes a natural remedy for the deranged functions of the stomach in particular, and through the sympathetic medium of that organ, for the atony of remote parts in general; and I shall hereafter shew, that in its medicinal applications it certainly imparts additional activity to many remedies, while it renders the stomach and system more susceptible of their salutary energies. As an essential ingredient in the provender of herbivorous animals, it may I think be admitted as a fact, that its importance is in an inverse ratio with the nutritive powers^[142] of the food, and we accordingly find, in conformity with that universal scheme of self-adjustment and compensation, which influences all the operations of nature, that cultivation, which extends the nutritive powers of vegetable bodies, generally diminishes their bitterness in the same proportion; the natural history of the Potatoe offers a good illustration of this fact, for the roots of this useful plant which have been so greatly improved 80by culture, are in their wild state both small and bitter.^[143] Gummy matter, which seems to result from the first change of the sap, is undoubtedly rendered more digestible and nutritive by the presence of a bitter; pure gum is not very much disposed to yield to the assimilative functions; “it frequently passes through the bowels,” says Dr. Chapman,^[144] “very little changed, as I have witnessed a thousand times.” We see therefore the value of the bitter principle, in the economy of the Lichen Islandicus, which is intended as the food of animals in northern latitudes; we are told that boiled linseed constituted the sole diet of the people of Zealand during a scarcity of long continuance, on which occasion, symptoms of great debility occurred, attended with those of dyspepsia; so again Professor Fritze, in his Medical Annals, states that vegetable mucilage, when used as a principal article of diet, relaxes the organs of digestion, and produces a viscid slimy mucus, and a morbid action in the primæ viæ, an effect which analogy shews might be obviated by the addition of bitter extractive. For the same reason animals that feed in marshy lands, on food containing but little nourishment, are best defended from the diseases they are liable to contract in such situations by the ingestion of bitter plants.^[145] Upon these occasions nature is very kind, for the particular situation that engenders endemic diseases is generally congenial to the growth of the plants that operate as antidotes to them.

I have offered these views upon the subject of Bitter Extractive, from a conviction that they will essentially contribute to the establishing of just and philosophical notions, respecting the necessity and modus operandi of many vegetable tonics.

As the action of tonics is gradual, so their operation is not followed by that exhaustion consequent upon the use of diffusible stimulants.

The substances which compose the class of tonics are derived from the vegetable and mineral kingdoms; those of the former are generally bitter, and produce their effects by a primary action on the stomach, and are not absorbed into the circulation, as experiments upon Bitter Extractive have most fully demonstrated; those derived from the mineral kingdom, comprehending several of the metals, appear in some instances to pass into the circulation, although several of them, like the vegetable tonics, act primarily on the primæ viæ; I apprehend this observation applies to the nitrate of silver, which certainly possesses considerable powers as a tonic in certain cases of dyspepsia, for which it may perhaps be indebted to the bitterness which distinguishes it.

Substances of a fragrant smell,^[146] which produce upon the organs of taste a peculiar sensation of warmth and pungency, and occasion, when swallowed, a corresponding impulse upon the stomach, which is rapidly communicated to the remote parts of the body.

The vegetable bodies which constitute the class of aromatic stimulants are very intimately related with that of tonics; indeed in the most efficient vegetables of the latter kind, the two qualities are generally blended, and the transition from these to the more pure bitters and aromatics is so imperceptible, that it is extremely difficult to arrange them in different classes; Dr. Murray has accordingly in his classification not attempted to separate substances which are so intimately connected. Aromatic Stimulants, however, in a practical point of view, must be distinguished from tonics, as the former are valuable for the rapidity, the latter, for the permanency of their effects. Their characteristic properties appear to depend chiefly, if not entirely, on an essential oil which, when extracted from the vegetable, exhibits all its aromatic power in a very concentrated form.

Medicines of this kind, when administered for the purpose of dispelling wind from the alimentary canal, have been termed Carminatives.^[147] They would seem to act by imparting energy to the distended and weakened muscular coat of the stomach, by which the accumulated gas is propelled through the upper orifice; for this viscus, like the bladder, when greatly distended, becomes unable to relieve itself, partly in consequence of the exhausted state of the over-stretched fibres of its muscular coat, and partly perhaps from a contraction of the Cardia, or upper orifice; for it has been already stated that a loss of power, and spasmodic action, are often the simultaneous results of debility.

ASTRINGENTS.

Substances which, when applied to the human body, corrugate and condense its fibres, and at the same time, exert a tonic influence through the medium of its living principle.

Astringency in any substance may be at once recognised by the organs of taste; its power in corrugating the papillæ of the tongue, and in imparting a sensation of harshness and roughness to the palate, being too peculiar to be mistaken; this is a fortunate circumstance, for there does not exist any one chemical test by which we can invariably detect the property of astringency, since it is found to reside in many different classes of substances: thus, acids, especially the stronger mineral ones, are powerfully astringent; so are many of the metallic salts, as those of iron, zinc, copper, and lead; and some of the earths, when combined with acids, of which alum is a striking example. The vegetable kingdom, however, 82furnishes the greater number of astringent remedies; and chemistry has shewn that this property uniformly depends upon a peculiar proximate principle, characterized by its power of forming an insoluble compound with animal gelatine; to this principle the name of Tannin has been given. As tannin generally exists in union with gallic acid, and as the latter body is known by its property of striking an inky blackness with the salts of iron, solutions of this metal were long, but erroneously, regarded as the proper test of vegetable astringency; the fallacy of this is at once shewn by the habitudes of Catechu, one of the strongest of our astringents, but which, nevertheless, will not yield the smallest degree of blackness to the solutions of iron, because it contains only tannin, the true principle of astringency, without a trace of its usual associate the gallic acid. From the power which these substances possess of astringing, and condensing the animal solids, their medicinal properties are supposed to arise, and we may perhaps, in this instance, admit such a mechanical explanation; but astringents possess also some power over the living principle of the matter which they astringe, for they are capable of acting as permanent stimulants, of curing intermitting fever, and of obviating states of general debility. Astringents would seem to moderate the morbidly increased secretions of distant parts, and to restrain hemorrhage, by their corrugating influence upon the primæ viæ,^[148] which is extended by sympathetic action to the vascular fibre; it is not difficult for any person to conceive the possibility of such a sympathy, who has ever experienced the thrilling and singular feeling which is produced over the whole body, by the acerb taste of the sloe-juice. As however the primary operation of these bodies, by their actual contact with the animal fibre, must be much more powerful than that which can result from the mere sympathy of parts, we find that the efficacy of astringents is principally displayed in the cure of diarrhœa, or serous evacuations from the intestinal canal; their operation, in checking profuse fluor albus, gleet, and the inordinate secretions of other distant organs, is much less striking and unequivocal, and it is a question whether in many of such cases the benefit arising from their use may not depend upon their tonic powers. As the morbid excess of different evacuations may arise from various and opposite states of the living system, so may the individuals of the other classes become astringents; and we are bound to admit upon this, as we have on other occasions, the existence of absolute and relative remedies.

Narcotics, at the head of which stands opium, will frequently assume the character of astringents, by diminishing the irritability upon which increased discharges depend. In Diarrhœa, an astringent, properly so called, diminishes the flow of those acrid fluids into the intestines, by which their peristaltic motions are præternaturally increased, and it consequently represses the diarrhœa; a narcotic, under similar circumstances, might not repress the flow of the acrid matter to which I have alluded, but it would render the bowels less susceptible to its stimulus, and would therefore produce the same apparent alleviation, although by a very different mode of operation. There is yet a third species of remedy, which 83may operate in restraining a diarrhœa of this description; not by stopping the flow of acrid matter, nor by diminishing the irritability of the intestinal organs, as in the instances above recited, but, simply, by acting chemically upon the offending matter, so as to disarm it of its acrid qualities; such, for instance, is the nature of absorbent and testaceous medicines. In the cure of hemorrhage, if it be active, that is to say, connected with a state of strong tonic contractility of the blood-vessels, a very different remedy will be required as an astringent, than in cases of passive hemorrhage, in which the vascular fibres are in a state of relaxation or collapse. Sir Gilbert Blane has offered some valuable remarks upon this subject, with a view to settle the difference of opinion which has arisen respecting the treatment of flooding after child-birth. (Medical Logic, Edit. 2d. p. 100.)

Astringents are capable of being exclusively used as local applications, and when they are so employed for the purpose of stopping hemorrhage, they are termed Styptics.^[149] With respect to these latter agents it must be confessed, that great popular error still exists, much of which has evidently arisen from deductions drawn from the effects of such remedies upon inferior animals; thus have several substances gained the reputation of Styptics, from the result which may have followed their application to the wounded and bleeding vessels in the extremities of the horse and ass; whereas the fact is, that the blood-vessels of these animals possess an inherent power of contraction which does not exist in those of man, and to which alone the cessation of the hemorrhage, fallaciously attributed to the Styptic, is to be wholly attributed. In many cases an application may owe its styptic qualities to its power of coagulating the blood around the orifice of the wound; in this way the contact of heated metal will sometimes arrest the flow of blood from a cut surface.

LOCAL STIMULANTS.

This Second Division comprehends those medicinal substances, which have been generally classed under the head of Evacuants; for, as they stimulate particular organs, so do they occasion by their local operation, an increased secretion, or evacuation from them.

EMETICS.

Substances which excite vomiting, independent of any effect arising from the stimulus of quantity, or of that occasioned by any nauseous taste or flavour.

Before we can determine the modus operandi of emetics, it will be necessary to take an accurate view of the phenomena and pathology of vomiting. 84It is an important fact that any extraordinary stimulus applied to the stomach, instead of increasing its motions, as it would in other instances, actually inverts them: the wisdom of such a peculiar provision is manifest; it is intended to prevent the protrusion of the food into the duodenum before it has undergone those necessary changes in the stomach, by which it is prepared for the more elaborate process of chylification. The act of vomiting, however, is not effected, as Dr. Haygarth formerly supposed, by the sole influence of the stomach; the brain is an important accessary: Dr. Majendie goes so far as to attribute the operation of vomiting, exclusively, to the agency of this latter organ upon the abdominal muscles, and regards the stomach as a mere passive instrument in the act;^[150] this doctrine was supported in an elaborate experimental memoir, presented by this indefatigable physiologist to the Royal Institute of France in the year 1812.

Although we shall not be disposed to receive this theory in its full extent, yet we cannot hesitate to admit that the influence of the nervous system is indispensably necessary for producing vomiting; and we accordingly find that this act will not take place, however forcibly the stomach may be goaded by emetics, where the energy of the nervous system is suspended, as in cases of profound intoxication, or in violent wounds and contusions of the head; while if the brain be only partially influenced, as by incipient intoxication, or by a less violent blow upon the head, its irritability is increased instead of being paralysed, and vomiting under such circumstances is excited by the slightest causes: the fact of such opposite results being produced by the same impulse in different degrees of intensity, is no less curious than instructive. Dr. Richard Harrison, in his Gulstonian Lecture before the College of Physicians, treated the subject of vomiting with much ingenuity, and I am disposed to adopt the views which he offered. He observed, that although the experiments of Majendie sufficiently testify the importance of the pressure of the abdominal muscles upon the stomach in the act of vomiting, and which can only be explained by the influence of the brain and nervous system, yet that he has attributed too much to their agency; “it appears to me,” continued he, “that vomiting may be explained in the following manner:—the irritation of the stomach makes a call upon the brain for the aid of the diaphragm and the abdominal muscles, in order to expel its contents; the diaphragm then becomes contracted and fixed, the ribs drawn down, and the abdominal muscles drawn inwards, so that the stomach is pressed on all sides by voluntary muscles, which, together WITH ITS OWN CONTRACTION, expel the contents.” Now it must be obvious that where the brain, from oppression or injury, is unable to transmit its influence to these muscles,^[151] and disregards the call of the stomach, vomiting can only be excited with difficulty, or it will be prevented altogether.

85Under such circumstances venesection may in some cases prove a powerful adjuvant, by unloading the vessels of the brain, and thus restoring to the nervous system its necessary excitability; where its powers have been paralysed by the operation of a narcotic, a copious draught of some vegetable acid, or the affusion of cold water upon the surface of the body may impart efficiency to an emetic; the operation of Nightshade and some other narcotic poisons may be adduced in farther illustration of this subject;—an excessive dose of the Atropa Belladonna produces symptoms of alarming stupor, and so difficult is it to evacuate the stomach under such circumstances, that as much as fourteen grains of Tartarized Antimony have been administered without effect: now if in such a case a copious draught of some vegetable acid be given, the emetic will be more likely to succeed: here then we perceive, that the brain, being paralysed by a narcotic poison, is unable to lend its aid to the muscles requisite for the operation of vomiting, until its energies are restored by the anti-narcotic powers of a vegetable acid. The practical precaution which this view of the subject affords, is extremely important,—not to allow the apparently inactive state of the stomach to induce us, inconsiderately, to augment the dose of an emetic: for although the stomach, for the reasons just stated, may be unable to void its contents by vomiting, it may nevertheless retain its sensibility, and be therefore liable to inflammation: Dr. Harrison has reported a case of this kind, where the practitioner, in attempting to excite emesis in an epileptic patient, by a very large dose of sulphate of zinc, produced an inflammation in the viscus that terminated fatally.

Vomiting may also be produced by the primary operation of certain agents upon the brain, by which its energy is disturbed, as by narcotics, or by the motions of swinging, whirling, and sailing: in such cases, the series of actions necessary for the establishing of vomiting, commences in the brain, and is propagated by nervous sympathy to the stomach.

When an emetic is taken into the stomach, an interval of twenty minutes or longer, usually passes without any apparent effect; an uneasy sensation, which we term nausea, is then felt, and this continues to increase until vomiting begins; here then we perceive are two distinct stages, each of which is marked by its own proper symptoms; the relative intensity and duration of which will be found to vary according to the nature of the exciting causes; thus some Emetics, as Sulphate of Zinc, act without occasioning much nausea, while others, as Tobacco excite it to a degree which is far greater than is proportioned to their emetic power: this is a fact of great importance in directing us in the selection of an Emetic, for we shall find that in some diseases it is a great object to avoid that state of system which invariably accompanies nausea, while in others it affords the best mode of answering an important indication of cure.

Nausea would seem to depend upon the exertions of the stomach and muscles, not being proportioned to the effects of the brain, in order to produce vomiting. Where this balance however is maintained, as during the operation of an ordinary emetic, the following are the symptoms which characterise the two stages;—while the nausea only is present, the countenance is pale and shrunken, the pulse feeble, quick, and irregular, and there is a feeling of cold; but as soon as vomiting commences, the face becomes flushed, the pulse quicker and stronger, although it seldom returns to its natural standard, until some time after the vomiting has ceased. 86A degree of languor, a disposition to sleep, and a general moisture upon the skin, are the circumstances which occur after the total cessation of the paroxysm.

The feeble state of the circulation, as indicated by the pulse, and the general coldness and languor experienced during a paroxysm of nausea, are to be ascribed to those sympathetic relations by which the brain, stomach, and heart, are reciprocally influenced.

The advantages to be obtained from the administration of an emetic in the cure of disease, may either depend upon its primary, or secondary operations, that is to say, upon the mere evacuation of the stomach, or upon those changes which occur in distant parts from sympathy; and the judicious practitioner, in the selection of an emetic, will always be guided by the nature of the indication which he intends to fulfil; if his object be to evacuate the stomach quickly and completely, he will avoid those emetics that are distinguished by their nauseating tendency, as in cases of disease which depend on a disordered state of stomach, connected with undue distention, and the presence of acrid and indigestible matter; if, on the other hand, his intention be to influence some remote organ through the sympathetic powers of the stomach, an emetic of an opposite tendency may be better calculated to answer such indications: in some cases, he is to seek a beneficial result from the mechanical action of the diaphragm and abdominal muscles, by whose pressure the gall-bladder and hepatic ducts are emptied of their contents, and hence jaundice, arising from the obstruction of biliary calculi, has been suddenly removed by the concussion of an emetic: a similar pressure upon the thoracic viscera may occasion expectoration, and relieve the bronchial vessels in cases of asthma, catarrh, and croup.

Vomiting, when produced by the operation of a mild emetic, does not appear to exhaust the excitability of the stomach, but on the contrary to increase its tone; for we generally find the process of digestion is carried on more vigorously afterwards; although it is probable that, by frequent repetition, a different result would be obtained, and we should find that its motion would become liable to inversion by slight stimuli: we may therefore question the propriety of that practice which is so strenuously recommended by Hippocrates,^[152] and other ancient physicians, to administer emetics frequently to those in health, in order to prevent the incursions of disease.

The benefits arising from the secondary effects of an emetic are numerous and extensive. It has been observed that during nausea the force of the circulation is considerably abated, hence the use of these remedies in hemorrhage; and, as the energy of absorption is generally in an inverse ratio to that of the circulation,^[153] we frequently obtain from a nauseating 87dose of an emetic, considerable assistance in the treatment of anasarca, and other dropsical swellings. Those medicines that are liable to produce at once, full vomiting, without any previous stage of nausea, are of course less calculated to fulfil such indications. In the same manner we should select a nauseating emetic, when our object is to promote the passage of a gall stone through the ductus communis, for the nausea so excited will relax the duct, while the mechanical concussion tends to push the obstructing matter forward. On the other hand, whenever our object is to evacuate the stomach, and to prevent absorption, we must take care to cut short the nauseating stage; a precaution which is highly important in the treatment of a case of poisoning. The state of the stomach produced by vomiting is very frequently extended, by sympathy, to the vessels of the skin; in consequence of which, a diaphoresis not unusually follows the operation. In the different varieties of febrile disease, this circumstance stamps additional value upon the class of Emetics; while, at the same time, that they eject any offensive matter which may be present in the stomach, they thus control the accelerated circulation.

From the violent muscular exertions which take place in the act of vomiting, the administration of an emetic may be very injurious in certain 88states of the body. In consequence of the pressure applied to the descending aorta, and the interrupted circulation through the lungs, from impeded respiration, the blood returns with difficulty from the head during a paroxysm of vomiting, and in plethoric states of the body, or in cases of determination of blood to the cerebral or pulmonary organs, the act of vomiting cannot be considered as free from danger. The concussion of an emetic may also produce mischief in the advanced stage of pregnancy, and in hernia and prolapsus uteri; while in extreme debility, there is the danger of a syncope being produced, from which the patient may never recover, as I once witnessed in the last stage of Phthisis, where an emetic was imprudently given, with the intention of dislodging the pus with which the lungs were embarrassed.

By violent and protracted retching, a person will sometimes become jaundiced; the stomach, diaphragm, and abdominal muscles, are, under such repeated efforts, apt to be rendered, to an eminent degree, irritable; so that at each effort of the former to discharge its contents, the latter will frequently be thrown into strong spasmodic contractions, and the liver together with the gall bladder will be suddenly caught, and, as it were, squeezed in a powerful press; in consequence of which the bile will regurgitate, and be carried into the Venæ cavæ; for Haller has shewn with what facility a subtle injection, when thrown into the hepatic duct, will escape by the hepatic veins; and upon which Dr. Saunders observes, “I know this to be a fact, for I have ascertained by experiment, that water injected in the same direction, will return by the veins in a full stream, though very little force be used.” When a jaundice is thus produced it will gradually disappear without the aid of any medicine; the kidneys are the principal means by which all unnecessary bodies are extracted from the circulating mass, a portion of bile will therefore under such circumstances be eliminated in every discharge of urine.

The different emetics employed in practice are derived from the vegetable and mineral kingdoms, some of which appear to produce their effects by an immediate impression upon the nerves of the stomach, while others require to be absorbed into the circulation before they display their energies. Ipecacuanha would seem to act primarily on the stomach, but Tartarized Antimony has been found, by experiment, to occasion vomiting, when injected into the veins of an animal; while the other mineral emetics, viz. the preparations of Copper and Zinc, undoubtedly operate on the stomach, and without inducing much nausea.

CATHARTICS:

Medicines which quicken or increase the evacuation from the intestines, or which, when given in a certain dose, occasion purging.

These remedies, from a general difference in their modes of operation, have been classed under two divisions—Laxatives and Purgatives. The former operate so mildly that they merely evacuate the contents of the intestines, without occasioning any general excitement in the body, or even stimulating the exhalant vessels of the canal; the latter produce a considerable influx of fluids from these vessels, and extend their stimulant effect to the system in general; and where these effects are very violent, the purgative is further distinguished by the epithet Drastic. Laxatives then may be said to empty the bowels simply, and to carry off extraneous 89matter, which is out of the course of the circulation; but purgatives, as they occasion a constitutional effect, may be made subservient to very important purposes. The effects of a purgative may depend upon three different modes of operation; viz.

 

1. By stimulating the muscular fibres of the Intestines, whence their peristaltic motion is augmented, and the contents of the bowels more quickly and completely discharged.

 

2. By stimulating the exhalent vessels, terminating in the inner coat of the intestines, and the mouths of the excretory ducts of the mucous glands; by which an increased flow of serous fluids takes place from the former, and a more copious discharge of mucus from the latter; the effect of which is to render the fæcal matter thinner and more abundant.

 

3. By stimulating the neighbouring viscera, as the Liver and Pancreas, so as to produce a more copious flow of their secretions into the intestines.

It appears that different purgatives have very different powers in relation to the several modes of operation above specified; some medicines, for example, urge the bowels to evacuate their contents by an imperceptible action upon the muscular fibres, and little or no increase of serous discharge attends the evacuation, such are Manna, Sulphur, and Magnesia; there would seem, moreover, to be certain bodies that have the property of increasing the peristaltic motions by operating as mechanical stimulants upon the fibre; it would not be difficult to derive many illustrations of this fact, from the history of herbivorous quadrupeds, and I have been disposed to consider the harsh and coarse texture which certain grasses assume in moist situations, as a wise provision in Nature to furnish an increased stimulus to the intestines of the animals who feed upon them, at a time when their diminished nutritive qualities must render such a result desirable; but the operation of a mechanical laxative may be demonstrated by a more familiar example; the addition of bran to our bread, constituting what is known by the name of Brown bread, induces laxative effects, merely from the mechanical friction of the rough particles, or scales of the bran, upon the inner coats of the intestines, for the wheat without the bran in bread is not particularly laxative.^[154] Other cathartics stimulate the fibres to a much greater degree, and the effects are either confined to a part of the canal, or communicated to the whole range of the intestines, from the duodenum to the extremity of the rectum; Aloes will furnish a good example of the former, and Colocynth may be adduced as an instance of the latter mode of operation. Other cathartics, again, direct all their stimulus to the exhalant vessels, and are accordingly distinguished by the force with which they produce serous evacuations; and for which they were formerly denominated Hydragogues, such are Saline Purgatives, and certain vegetable bodies to be hereafter described. Dr. Cullen has even supposed that some of these medicines may act solely in this way, and 90without increasing directly the peristaltic motion; there is, however, as Dr. Murray very justly remarks, no proof of such an hypothesis, and it seems scarcely probable that any substance should act as a stimulant on these vessels, without at the same time stimulating the mobile fibres of the intestines. Mercurial Purgatives appear to possess, in an eminent degree, the power of exciting the functions of the liver, and of thereby occasioning an influx of bile into the intestines. From the indications which cathartics are capable of fulfilling, their utility in many diseases must be apparent; the extent of their importance and value were, however, never justly appreciated until the valuable publication of Dr. Hamilton on this subject, in which the author has pointed out with more precision than any preceding writers had done, the therapeutic principles which should regulate their administration. His practice has clearly proved that a state of bowels may exist in many diseases, giving rise to a retention of feculent matter, which will not be obviated by the occasional administration of a purgative, but which requires a continuation of the alvine stimulant, until the healthy action of the bowels is re-established. Since this view of the subject has been adopted, numerous diseases have received alleviation from the use of purgatives that were formerly treated with a different class of remedies, and which were not supposed to have any connection with the state of the alvine evacuations; thus in fever, the peristaltic motion of the intestines is diminished, and their feculent contents are unduly retained, and perhaps, in part, absorbed, becoming of course a source of morbid irritation; this fact has long been understood, and the practice of administering cathartic medicines under such circumstances has been very generally adopted; but until the publication of Dr. Hamilton, physicians were not aware of the necessity of carrying the plan to an extent beyond that of merely emptying the primæ viæ, and they did not continue the free use of these remedies through the whole progress of the disease.

Cathartics are essentially serviceable also in several diseases of the class Neuroses, which are generally intimately connected with a morbid condition of the alimentary passages; Chorea and Hysteria have been very successfully treated in this manner. The diseases incident to puberty in both sexes are also best relieved by a course of purgative medicines, and their effects in Chlorosis have conferred upon many of them the specific title of Emmenagogues.

But the therapeutical utility of Cathartics extends beyond the mere feculent evacuations which they may occasion. In consequence of the stimulating action which some of them exert upon the exhalent vessels, they abstract a considerable portion of fluid from the general current of the circulation, and are, on that account, beneficial as Anti-phlogistics. For the same reason they may act as powerful promoters of absorption, for there exists an established relation between the powers of exhalation and absorption, so that when the action of one is increased, that of the other is augmented.

Certain Purgatives, as I have just stated, exert their influence upon the neighbouring organs, and are calculated not only to remove alvine sordes, but to detach and eliminate foul congestions from the biliary ducts and pores.

With such facts before us, it is impossible to concede to the opinion of Dr. Hamilton,^[155] that the different species of purgative medicines do not 91possess distinct powers over the different species of matter to be evacuated; on the contrary, there is reason for reviving the ancient theory, too inconsiderately abandoned, and which acknowledged these different distinctions in the operations of cathartic medicines, under the appropriate names of Hydragogues, Cholagogues, &c.

The importance of cathartic medicines having been shewn, and the distinctions in their modes of operation established, it only remains to say a few words upon the subject of their abuse. All the remedies of this class, but more especially those of considerable power, require caution in their administration, even in those diseases where they are indicated by peculiar symptoms, especially if there be any tendency to inflammation, or to extreme debility, although this latter symptom is often rather apparent than real, and is at once removed by the brisk operation upon the bowels; during pregnancy and immediately after delivery, and during the flow of the menses, the prudent practitioner will use a discretionary caution in their exhibition. The too frequent use of these medicines will induce marasmus, and render the bowels so morbidly irritable, that purging is easily excited by the ordinary stimulus of our aliments; while in some habits the contrary obtains, and the resource to which the valetudinarian flies for relief only increases the torpor of the intestines, and confirms his costiveness.

The mode of adapting, combining, and administering Cathartics, will present subjects for our future consideration.

EMMENAGOGUES:

Medicines which are capable of producing the Menstrual discharge.

As Amenorrhœa, or retention of the menses, is generally the effect of a morbid state of the body, it follows that remedies capable of acting as Emmenagogues can only be relative agents, unless indeed we are disposed to accede to the opinion so generally maintained in the writings of the older physicians, but now generally discarded, that certain substances exert a specific^[156] action upon the uterus. It may certainly be asserted without fear of contradiction, that there are many substances which, when received into the stomach, have their stimulant operation more particularly determined to one part than to another; alkalics, for example, to the kidneys; cantharides to the bladder; mercury to the salivary glands, &c. Reasoning therefore by analogy, it was not unphilosophical to conclude, that similar medicines might exist with respect to the uterus; but experience has negatived the supposition, there being no proof of any of the substances styled Emmenagogues producing their effects by any specific influence upon the uterine system. If the term Emmenagogue be assumed conventionally, according to this view of the subject, it may be retained without any fear 92of error, otherwise it would be wiser to remove the name from our classification.

The suppression of the catamenia usually depends upon a debilitated state of the body, although it is sometimes the consequence of a plethoric diathesis; in the former cases tonics, in the latter, venesection may display the powers of an emmenagogue; upon which occasion, I have frequently derived the greatest benefit by cupping the patient upon the loins. Where the disease occurs in young women, about the age of puberty, it is very generally connected with extreme debility of the system; the preparations of iron, bark, and other invigorating medicines, are accordingly the most likely to succeed in its cure. Whereas in full florid habits, when the catamenia are suddenly suppressed, Laxatives, Diaphoretics, or blood-letting, afford the surest means of relief.

There are two other classes of medicine which may occasionally prove emmenagogue—Acrid Purgatives, which act upon the rectum, and hence by contiguous sympathy upon the uterus, as Aloes, &c. and Stimulating Diuretics, as Cantharides, the Turpentines, &c. which are supposed to excite the womb, sympathetically, by their stimulus upon the bladder. Nor is the advantageous influence of mercury to be overlooked, which, in cases of morbid action in the secreting functions, prove a Herculean remedy.

DIURETICS:

Medicines which increase the urinary discharge.

This effect is produced by very different modes of operation; and as some of them are mutually incompatible with each other, it is essential that we should understand the modus operandi of each individual of which the class consists, in order that we may direct its application with precision.

There is undoubtedly no tribe of medicinal agents more precarious in their nature and effects than that of Diuretics; this fact in a great measure depends upon the uncontrollable character of the organs upon which they act, but it must at the same time be admitted, that their failure frequently depends upon their modes of operation being directly incompatible with the state of the system at the time of their administration.

The following classification may perhaps serve to bring together the principal facts which are known upon the subject, and at the same time to display them in an order which is calculated to demonstrate their practical bearings and relations.

DIURETICS,

CL: I.—MEDICINES WHICH ACT PRIMARILY ON THE URINARY ORGANS.

1. By stimulating the secreting vessels of the kidneys, BY CONTACT.

a The medicines not undergoing any decomposition in transitu.

931. Potassa.

2. Potassæ Nitras.

3. Oleum Terebinthinæ.

4. Juniperus Communis.

5. Cantharides.

b The Medicines undergoing decomposition in transitu.

1. Potassæ Acetas.

2. Potassæ Super-tartras.

3. Scilla Maritima.

4. Colchicum Autumnale.

5. Copaifera Officinalis.

6. Spartii Cacumina.

CL: II.—MEDICINES WHICH ACT PRIMARILY ON THE ABSORBENTS, AND SECONDARILY ON THE KIDNEYS.

CL: III.—MEDICINES WHICH ACT PRIMARILY ON THE STOMACH AND PRIMÆ VIÆ, AND SECONDARILY ON THE ABSORBENTS.

1. By diminishing arterial action, and increasing that of Absorption.

1. Digitalis.

2. Nicotiana.

2. By increasing the tone of the Body in general, and that of the absorbent system in particular.

Bitter Tonics, &c. &c.

3. By producing Catharsis, and thereby increasing the action of the Exhalants directly, and that of the Absorbents indirectly.

1. Elaterium.

2. Jalap, &c. &c.

C. 1. Of Medicines which act Primarily on the Urinary Organs.

1. By stimulating the secreting vessels of the kidneys, by actual contact.

a The substance not undergoing any decomposition in transitu.

It is easy to imagine that any substance which is capable of entering the current of the circulation, and of stimulating the kidneys by a direct application to their secerning vessels, may occasion a more copious urinary discharge; in this manner the different saline^[157] preparations, Potass, 94Soda, Nitrate of Potass, &c. are brought to the kidneys in the course of the circulation, and exciting the vessels to an increased action, promote the secretion of a larger proportion of watery fluid from the blood, in consequence of which, the absorbents are indirectly stimulated in order to supply the deficiency, and in this manner dropsical swellings are reduced.

Water, as a simple diluent, will promote the action of the kidneys, and it is very judiciously remarked by Dr. Cullen, that by withholding the use of fluids in dropsy, you will diminish the quantity of fluids secreted, and allow the secretories of the kidneys to fall into a state of inactivity and collapse. This is a sufficient answer to those who defend the practice of enjoining an abstinence from all drinks in dropsy.

b. The diuretic remedy undergoing decomposition IN TRANSITU.

The digestive organs appear to possess the power of readily decomposing all saline compounds into which vegetable acids enter as ingredients, and of eliminating their alkaline base, which, being in the course of the circulation, carried to the kidneys, excites them into action, and promotes the excretion of urine; and it is probably in this way that the Acetate, Citrate, Super-tartrate, and other analogous combinations of Potass and Soda prove diuretic: on the other hand, it is equally evident that salts containing the mineral acids are not under the control of the decomposing powers of the chylo-poietic organs, and consequently do not undergo any changes in transitu, although some of these salts, as I have just stated, especially the more soluble ones, are absorbed entire, and prove diuretic. Sulphate of Potass, from its insolubility, is not readily absorbed, and its composition will not allow the developement of its base; we perceive therefore that it has not any tendency to produce an influence upon the urinary secretion.

Certain vegetable bodies likewise appear to occasion diuresis by a similar mode of operation, and it is worthy of notice that these medicines generally contain a bitter principle, which is probably separated by the analysing powers of the stomach; as exemplified in Scilla maritima; Colchicum autumnale; Lactuca Virosa; Gratiola officinalis; Spartium Scoparium (Summitates); Juniperus communis; Copaifera Officinalis (Balsamum,) &c. The stimulant powers of a bitter vegetable principle upon the primæ viæ, have already been fully noticed under the consideration of Tonics, (page 78), and it is reasonable to suppose, that an analogous principle, if introduced into the circulation, may exert a corresponding impulse upon the organs with which it comes into contact.

It particularly merits attention, that the diuretic operation of any body that acts by being absorbed, is at once suspended if catharsis follows its administration, whether in consequence of the largeness of its dose, its increased solubility, or from the effect of its combination with some purgative; for it is a law, that the processes of assimilation, and absorption from the duodenum, are arrested, or very imperfectly performed during any alvine excitement; the different effects of the saline compounds of the alkalies with tartaric acid, elucidate the truth of this law in a very striking manner—thus, Super-tartrate of Potass, or Cream of Tartar, in well regulated doses, acts, as we all know, upon the kidneys; the tartaric acid being, as I suppose in this case, abstracted and assimilated by the digestive process, and 95at the same time the alkaline base (Potass) eliminated, and subsequently carried into the circulation; but if we increase the solubility of the compound, by reducing it to the state of a neutral tartrate (soluble tartar), or by combining it with Boracic acid, or some body that has a similar effect; or what is equivalent to it, if we so increase the dose^[158] of the cream of tartar, that full catharsis follows its administration, then diuresis will not ensue, since no decomposition can take place under such circumstances, nor can it be carried by absorption into the circulation. Nitre and those salts which are carried to the kidneys without previous decomposition in transitu, are subject to the same law; for, if we combine them with purgatives, their presence can no longer be recognised in the urine, as I have ascertained by experiment. Oil of Turpentine in doses of two fluid-drachms, may so excite the urinary organs as to produce even bloody urine; whereas a fluid-ounce will scarcely occasion any apparent influence upon those functions, because the increased dose acts upon the bowels, and consequently prevents its passage into the circulation.

Sulphate of Magnesia does not readily produce any diuresis, because it operates upon the bowels, but the experiments of Vitet and Bracy Clarke have shewn, that if this saline compound be administered to the horse whose bowels are not easily affected by purgatives, it acts powerfully upon the kidneys;^[159] and I will take occasion in this place to observe that, on account of the inirritability of the bowels of the horse, diuretic medicines are more certain in their operation, than in the human subject; a fact which, in itself, shews the importance of attending to the state of the bowels, during a course of those diuretics which require to be absorbed before they can produce their specific effects.

Equally necessary is it to attend to the state of the vessels of the skin, for if during the administration of a Diuretic, these vessels be excited by external warmth, its action may be diverted from the urinary organs to the exhalants on the surface, and occasion diaphoresis; but if the surface of the body be kept cool, this diversion will not occur: so greatly indeed does cooling the surface determine to the kidneys, that the usual diaphoretic medicines may, by an attention to this circumstance, be converted into powerful diuretics.

C. II. Medicines which act Primarily on the Absorbents, and Secondarily on the Kidneys.

It has been shewn, in the former division, that by increasing the action of the kidneys, we diminish the quantity of water in the blood, and consequently occasion an extraordinary action of the absorbents to supply the deficiency, whence dropsical accumulations disappear; it remains to be stated that an operation, which may be considered the converse of the one just described, is not unfrequently established: the absorbent vessels, in 96this case, are first roused to extraordinary action, and the blood therefore becomes surcharged with serous matter, in consequence of which the kidneys are stimulated, and it is eliminated through the urinary passages: so that in the former case the absorbent may be said to be called into action by the kidneys, while in the latter, the kidneys are obviously subservient to the increased energy of the absorbent system. The preparations of Mercury are perhaps the only medicinal bodies which we can strictly consider as specific stimulants to the absorbent system; and of their power in directly acting upon these organs there are such ample proofs, that it is unnecessary to adduce any additional evidence upon the subject. In instances of increased absorption from the agency of other medicines, the effect must be considered as rather arising from their secondary than primary operations; the most important of which will constitute objects of inquiry in the succeeding divisions of the subject.

C. III. Medicines which act Primarily on the Stomach or System, and Secondarily on the Urinary Organs.

A Diuretic effect is very frequently occasioned by substances which act on the stomach and primæ viæ, producing a peculiar state of these organs, which sympathetically affects the whole body, and more particularly the absorbent system, and the vessels concerned in the secretion of urine from the blood. As this primary influence upon the stomach, and the effects to which it gives rise in remote parts, are very different in their character, according to the nature of the remedy employed, and the state of the system at the time of its administration; the present attempt to investigate and generalize these relations, and to adopt them as the basis of a classification, may ultimately lead the practitioner to some distinctions of practical utility.

1. By diminishing Arterial Action, and increasing that of Absorption.

It would appear that the action of the vessels employed in the circulation of the blood, and the energy of the absorbents are, to a certain extent, antagonist powers; the experiments of Majendie demonstrate that the absorption of a poisonous substance is retarded by a plethoric, and accelerated by a depleted state of the sanguineous system; the fact is practically established by numerous phenomena in pathology. Dr. Blackall has very satisfactorily shewn the existence which subsists between increased arterial action and diminished absorption. Hence it follows that remedies capable of controlling the circulation may affect the activity of absorption, increase diuresis, and cure dropsy; in this manner the Digitalis Purpurea acts as a sorbefacient, and it may be remarked that it seldom or never produces its diuretic effects, without a concomitant reduction of the frequency of the pulse; its power too appears only when it is administered in dropsy; in a state of health it will reduce the pulse, but not increase the discharge of urine. Tobacco has also somewhat analogous powers in promoting absorption, and its operation is accompanied with a corresponding depression of vascular action. Venesection, upon the same principle, may occasion, in certain cases of dropsy, a discharge of the accumulated fluid.

That diminished absorption, and the consequent accumulation of serous fluids in the cellular texture, and different cavities, frequently depends upon general debility is very obvious, whence fevers, whether of the intermittent, or continued kind, which have been long protracted, are followed by œdematous swellings. In states of extreme debility the exhalant vessels would seem, from their laxity, to permit the thinner parts of the blood to pass too readily through them; this is proved by the circumstance that palsied limbs, in which such a laxity may be presumed to exist, are frequently affected with œdema, and the truth of this explanation is still farther corroborated by the advantages which accrue on these occasions from the mechanical support of pressure from bandages. In such cases, those remedies which are capable of renovating the vigour of the body can alone prove of any signal service. Dr. Blackall presents us with an illustrative case of this nature, on the authority of Mr. Johnson of Exeter, in which the tonic powers of well fermented bread occasioned in the space of a few hours an effect so powerfully diuretic, as to have cured sailors on board of the Asia East Indiaman, who had been attacked with Dropsy, in consequence of the use of damaged Rice.

Thus then do Diuretics, in some cases, cure by Evacuating, while in others, as in the instance above cited, they Evacuate by curing.

A case has lately occurred in my own practice, which not only affords a striking illustration of the present views, but is well calculated to convey to the inexperienced practitioner a very instructive lesson of caution. A man of the age of thirty-five, of the most dissolute habits, was attacked after a debauch of several days’ continuance, with inflammatory symptoms in the chest; a very large quantity of blood was suddenly abstracted, and the bleeding was repeated after the interval of a few hours. The respiration became laborious, and I was desired to visit the patient; I found that little or no urine had been evacuated since the attack, and that there were evident symptoms of effusion, the legs were swollen, and the difficulty of breathing was rapidly increasing. Under these circumstances I directed a large dose of Ammonia with some stimulating diuretics, which were to be repeated at short intervals. On the following day the distressing symptoms had subsided, a large quantity of urine had passed, and the patient expressed himself greatly relieved; unfortunately, however, in consequence of a slight increase of his distress in the evening, an injudicious friend in attendance, took more blood from the arm—the dropsical effusions rapidly increased, and life was extinguished in the course of three days by confirmed Hydrothorax.

3. By producing Catharsis, and thereby increasing the action of the Exhalants directly, and that of the absorbents indirectly.

It has been already stated, under the consideration of Cathartics, that certain medicines of that class excite the exhalants of the alimentary canal, and occasion a very copious discharge of serous matter: by this operation the blood is deprived of a large portion of water, and the absorbents are thus indirectly stimulated to supply the deficiency; Elaterium, and some other hydragogue cathartics, may be thus employed with extraordinary 98success for the cure of certain forms of Dropsy, where the vital powers of the patient can sustain the violence of the remedy;—in the whole circle of medicinal operations there is nothing more wonderful than this, that an impression made on the internal surface of the primæ viæ, by a few particles of matter, should thus convey by magic as it were, an impulse to the most remote extremities, rousing their absorbents to action; and, in case of œdema there, awakening the sleeping energies of these vessels, which like millions of pumps at work, transmit the morbid fluid to the intestines and urinary passages, effecting a detumescence of the hydropic limbs in the course of a few hours, and thus affording a striking illustration of the sympathetic action of medicines, and an instructive example of the operation of those of the sorbefacient class.^[160]

The observations which I have thus offered will lead the practitioner to select the particular diuretic which is best calculated to fulfil the indications of each individual case; and they will at the same time point out those which cannot be administered in combination, without a violation of the law of medicinal compatibility. With respect to the general efficacy of these medicines it may be stated, that where the disease originates from organic affections of the chylo-poietic viscera, it will not be cured by the mere evacuation of the water by diuretics; but that where it has taken place from diminished absorption, these remedies may be reasonably expected to effect a cure.

DIAPHORETICS.

The term Diaphoretic has been applied to those medicines which increase the natural exhalation of the skin, and when they act so powerfully as to occasion sweating, they have been commonly distinguished by the name of Sudorifics, but as no difference exists between these remedies, but in the degree of force with which they act, we may very properly comprehend the whole under the general title of Diaphoretics: the fluid effused is also in both cases similar, but in the one it is discharged more slowly, and is carried off by the conducting^[161] power of the air, in the insensible form of vapour, while in the other case it is so copiously effused from the exhalant vessels, as to appear in the liquid form.

As obstructed perspiration may depend upon very different, and even opposite states of the system, so may the most adverse medicines fall under the denomination of diaphoretic remedies.

In some affections, a deficient diaphoresis may be associated with increased vascular action, and in others, with a slow languid circulation.

99Diaphoretics may be considered as operating, either by directly stimulating the cutaneous capillaries;—by increasing the general action of the vascular system;—by relaxing the morbidly constricted mouths of the perspiratory vessels;—or, lastly, by producing at once both the latter of these effects.

In conformity with the plan adopted on other occasions, I shall proceed to investigate the powers of this class of medicines, according to their supposed modes of operation.

DIAPHORETICS

Occasion their effects—

I. By Stimulating the Cutaneous Capillaries.

A. By external application.

The Stimulus of Heat, Frictions, &c.

B. By Medicines which enter the circulation and stimulate the cutaneous vessels by contact.

Mercurials—Sulphur.

C. By Medicines which act on the surface sympathetically, through the medium of the Stomach.

Cold Drinks, &c.

II. By Increasing the General Action of the Vascular System.

Violent Exercise—Ammonia—Guaiacum—Alcohol—Warm Bath.

III. By relaxing the morbidly constricted mouths of the Perspiratory Vessels.

Antimonials—Cold Affusion—Venesection—Saline Diaphoretics.

The action of the cutaneous vessels may be augmented by heat, without necessarily increasing, at the same time, that of the heart and arteries; hence it is that heat is, of itself, often sufficient to produce sweating, while it generally accelerates the operation of a sudorific medicine. To this general proposition, however, there are some very important exceptions; and, indeed, in certain conditions of the cutaneous surface, the stimulus of heat will be even found to impede, rather than to promote, diaphoresis; thus in the hot stage of a continued fever, there would seem to exist a peculiar constriction of the perspiratory vessels, accompanied with extreme heat and dryness. In such a state, remedies of the third class must be applied, or conjoined with those of the former. The warm bath may be said to partake of all the qualities upon which our classification is founded; it will stimulate the cutaneous capillaries,—increase vascular action, generally, and, by its emollient powers, relax the morbidly constricted mouths of the perspiratory vessels. During the ardent heat of fever, the external application of cold is the most efficient sudorific, as the valuable reports of Dr. Currie have very satisfactorily established.

Although the external application of cold was not often employed in the hot stage of fever, until within the last thirty years, yet the administration of cold drinks appears to have been practised by the ancients, as an expedient to produce perspiration. Galen, and his immediate disciples, as well as the physicians of the sixteenth century, seem to have frequently 100administered cold water for the purpose of exciting sweat in fevers.^[162] Celsus also describes the beneficial effects which arise from copious draughts of cold water in ardent fevers, “fereque post longam sitim et vigiliam, post multam satietatem, post infractum calorem, plenus somnus venit, per quem ingens sudor effunditur, idque præsentissimum auxilium est.”^[163] Cold water, when introduced into the stomach in the hot stage of fever, must produce its diaphoretic effect through the sympathetic relation which subsists between that organ and the skin. Nauseating doses of Antimony, and of other emetics, occasion a relaxation of the surface from the same mode of operation, and in this latter case, if the force of the circulation be at the same time increased by tepid diluents, the diaphoretic effect is more certain and considerable.

Alcohol, Guaiacum, and other powerful stimulants, produce their effects by merely accelerating the circulation; but in employing such remedies for the purpose of exciting sweat, we must be careful to adapt them to the circumstances of the case, and to the degree of action which prevails. In all febrile diseases attended with much increased heat, or connected with local inflammation, diaphoretics of this description must be very cautiously administered, for by accelerating the circulation they might counteract any benefit which they would otherwise confer by relaxing the vessels of the skin. In the whole history of medical opinions there is scarcely a theory which has proved so fatal in its practical applications as that maintained by Van Helmont, and his disciples, viz. that acute diseases were to be cured by expelling some morbific matter, after its proper concoction—a theory which suggested the administration of the most stimulating sudorifics, together with high temperature^[164] in every grade of febrile exacerbation. The fatal effects of such a practice during the seventeenth, and early parts of the eighteenth centuries, are incalculable, and may be very satisfactorily contrasted with the beneficial results which have accrued, in the same diseases, in the present age, from the use of diaphoretics of the refrigerant kind.

Saline Diaphoretics, as they readily pass with the chyle, may be supposed to enter the circulation, and be thus brought to act, directly, on the cutaneous vessels; at the same time it seems extremely probable that such remedies may also occasion an impression on the stomach, which is sympathetically communicated to the vessels of the skin; they have undoubtedly little or no influence on the general vascular system, and neither augment the force nor the velocity of the circulating current.

It is not, however, in febrile affections alone that this class of remedies proves highly beneficial; the very intimate sympathetic connection which subsists between the functions of the lungs and skins, renders the use of such medicines particularly advantageous in the cure of the diseases incident to the former of these organs; a fact upon which we shall hereafter offer some remarks under the history of Expectorants.

So again, in the treatment of bowel affections, in consequence of the 101intimate relation which exists between the cutaneous capillaries and those of the internal organs, gentle diaphoretics offer a valuable resource in their cure. How frequently do Diarrhæa, Enteritis, &c. ensue from the sudden suppression of perspiration by cold?

From the influence which these medicines exert upon the extreme vessels of the skin, they are also highly serviceable in various obstinate cutaneous affections, as Herpes, Lepra, &c.

As evacuating the serous part of the blood must necessarily have an indirect effect in promoting absorption, Sudorifics have been occasionally exhibited in Dropsy, especially in that form of the disease called Anasarca. It has been already observed that cases too frequently occur in which the discharge of urine cannot be increased by art; upon such occasions practitioners have sometimes had recourse to a trial of Sudorifics,^[165] but from the great difficulty which generally exists in exciting sweating in such affections, the indication has rarely been fulfilled. Where however a sudorific does succeed, it is less liable to debilitate than the other alternative of a drastic purgative.

There is still another point of view in which the therapeutic importance of Diaphoretics may be considered. It is generally acknowledged that by cutaneous transpiration a portion of excrementitious matter is ejected from the system; hence by the failure or imperfect performance of this function, a deleterious fluid is retained which may give origin to disease; to such a cause may perhaps be attributed the generation of Calculi, and other diseases of the urinary system, as we shall have occasion to notice under the head of Lithonthryptics.

The increased efficacy which these medicines derive from combination with each other, will form a subject of interesting enquiry in the succeeding essay.

EXPECTORANTS.

Medicines which are supposed to be capable of facilitating the excretion of mucus from the breast, ex pectore, that is, from the trachea, and cells and passages of the lungs.

If the term Expectorant be intended to express a medicinal substance which has the power of promoting the expulsion of fluid from the lungs, by some specific action on the parts concerned, we can have no hesitation in at once rejecting the word, and denying the existence of such remedies: if, however the term be received, conventionally, as comprehending 102all those substances which are capable, according to the state of the system in each particular case, of producing expectoration, it will be extremely proper to recognise, and practically useful to retain, such a class of medicinal agents. In order that their modus operandi may be correctly understood, the following classification is submitted to the reader.

A CLASSIFICATION OF EXPECTORANTS,

CL: I—MEDICINES WHICH INCREASE PULMONARY EXHALATION, AND THEREBY DILUTE THE MUCUS IN THE FOLLICLES OF THE LUNGS.

a. By removing constriction of the Pulmonary Exhalant vessels.

Blisters.

Venesection.

Nauseants.

b. By stimulating these vessels by the actual contact of a medicinal substance.

Allium.

Scilla?

The different Balsams.

fœtid Gums.

c. By stimulating the top of the trachea, and thereby increasing the action of the exhalant vessels of the lungs, by a species of Contiguous Sympathy.

Stimulating Lozenges, Linctusses, The Inhalation of certain vapours, &c.

CL: II.—MEDICINES WHICH DIMINISH THE INORDINATE FLOW OF FLUID INTO THE LUNGS, AND RENDER THE EXPECTORATION OF THE REMAINDER MORE EASY.

a. By removing the debility of the Exhalants.

Sulphate of Zinc.

Bitter Tonics.

b. By increasing the power of the Absorbents.

Digitalis.

Nicotiana.

c. By determining to the skin by gentle diaphoresis.

Tartarized Antimony.

d. By exciting serous discharges from the bowels.

Saline Purgatives.

CL: III.—MEDICINES WHICH OPERATE, MECHANICALLY, IN PROMOTING THE REJECTION OF ACCUMULATED MUCUS.

a. By stimulating the muscles of Respiration.

Ammonia.

b. By exciting vomiting, and thereby compressing the thoracic viscera.

Emetics.

a. By removing constriction of the Pulmonary Exhalant vessels.

There can be no doubt but that, in certain states of disease, the exhalants of the lungs, like those of the skin, are affected by a spasmodic constriction, in consequence of which the usual quantity of fluid for the lubrication of these parts, is not effused, whence a train of morbid phenomena arise; this appears to happen in Pneumonia, Asthma, and certain other diseases of the pulmonary organs. In order to remove such a constriction, remedies of the Antispasmodic class may be exhibited with advantage; nauseating doses of Tartarized Antimony, or of Ipecacuanha, are likewise calculated to fulfil the same indication, by an operation analogous to that by which Diaphoresis is produced. If the term might be allowed we should call such remedies Pulmonary Diaphoretics. It is in this way that Venesection, Blisters, and other anti-phlogistic remedies, may in certain states of the lungs restore a healthy excretion from these vessels.

b. By stimulating the Pulmonary Exhalants, by the actual contact of a medicinal substance.

There certainly appear to be substances which enter the circulation, and are more peculiarly determined to the pulmonary vessels, since their odour is to be distinctly recognised in the air that is expired. Garlic may be adduced as an example of this kind; so penetrating is its odorous principle, that if it be only applied to the soles of the feet it may be perceived in the breath. Such substances may stimulate the exhalant vessels through which they pass, and by this stimulus the secretion may be increased, and the mucus contained in the follicles diluted, so as to be poured out in a less viscid form, and consequently in a state to be more easily brought up by expectoration.

c. By stimulating the top of the trachea, and thereby increasing the activity of the Exhalant vessels of the lungs, by a species of contiguous sympathy.

The salutary operation of those various remedies, which are allowed to pass slowly over the fauces, sufficiently establish the fact which is here announced. In this manner I apprehend that much benefit may arise from the use of a Linctus, and I am satisfied from experience that certain cases of hoarseness are to be frequently removed by such an application of stimulating syrups.

The inhalation of certain vapours will also enable us to make a more direct application to these parts; as, however, it is my intention to dedicate a chapter to the consideration of this form of remedy, it is unnecessary to dwell upon it in this place.

a. By removing the debility of the Exhalants.

It not unfrequently occurs in persons either debilitated by age or disease, that the exhalant vessels of the lungs lose their tone, and pour out a larger quantity of fluid than is necessary for the lubrication of these organs; this is particularly observable in the disease called humoral asthma, and in the catarrh of old persons: if this excess be restrained by strengthening the tone of the system generally, or by astringing these vessels in particular, the expectoration of the remainder will be rendered much more easy. According to my experience, sulphate of zinc displays considerable powers in moderating this effusion of fluid, and it appears to produce this effect by increasing the tone of the exhalant vessels of the lungs; several medicines also, which are included in the former division of this classification, may, by stimulating these organs, not only promote the exhalation when it is too scanty, but repress it when it is too abundant.

b. By increasing the power of the Absorbents.

In some cases, the mucous inundation may not depend upon any fault in the exhalants, but upon a torpid state of the pulmonary absorbents: our remedy for this evil is to be found amongst that class of medicines which have the power of promoting absorption, as small doses of some mercurial preparation, Digitalis, and perhaps Nicotiana, &c.

c. By determining to the skin by a gentle diaphoresis.

It is evident that an increase of the cutaneous exhalation is generally attended with a relative diminution in the other serous excretions of body; this is so obvious with respect to our urinary discharge, that every person must have noticed the variation of its quantity at different seasons of the year: in like manner the exhalation from the lungs, although less capable of becoming an object of observation, is not less affected by the state of the cutaneous discharge; hence medicines capable of promoting it, are calculated to diminish the quantity of serous exhalation from the lungs; and it is upon this principle, that well regulated doses of the compound powder of Ipecacuan], frequently furnish the oppressed asthmatic with a valuable resource.

d. By exciting serous discharges from the bowels.

Upon the principle announced in the preceding section, the operation of a saline cathartic may relieve the pulmonary organs when loaded with a preternatural accumulation of fluid, and consequently assist expectoration. On the contrary, if the exhalation be deficient, this class of remedies may increase pulmonary irritation, and check expectoration, a fact which coincides with the concurrent testimony of many able practitioners.

a. By imparting vigour to the respiratory muscles, engaged in the act of expectorating.

It must be admitted that, to a certain extent, expectoration is a voluntary operation, connected with the action of a variety of muscles, which in a state of extreme debility are not easily excited into action: every practitioner must have noticed this fact during the treatment of the coughs of exhausted patients, and have witnessed the distress necessarily arising from it; in this condition, the exhibition of a stimulant may so far renew the exhausted excitability of these organs, as to enable them to undergo the necessary exertions.

b. By compressing the thoracic viscera, through the operation of an emetic.

The beneficial results which frequently attend the concussion of an emetic, in cases of mucous accumulations in the lungs, are too well known and understood to require much elucidation: in the act of vomiting the thoracic viscera are violently compressed, the neighbouring muscles are also called into strong action, and both expiration and inspiration are thus rendered more forcible, and the expulsion of mucus from the cavity of the lungs necessarily accomplished.

The safety and expediency of such a resource must, however, in each particular case be left to the discretion of the medical practitioner.

Besides the remedies above enumerated, there are some others which afford relief in certain coughs, and have therefore in popular medicine, been considered as Expectorants; but their operation, if they exert any, is to be explained upon principles altogether different from that of facilitating expectoration, and will more properly fall under the head of Demulcents.

Atmospheric changes, in relation to moisture and dryness, deserve some notice before we conclude the history of expectorant agents: the subject teems with curious and important facts, and the advantages which the asthmatic patient derives from such changes merit farther investigation. That the lungs are constantly giving off aqueous vapour is made evident by condensing the expired air on a cold surface of glass or metal; and it is easy to imagine that when the atmosphere is saturated with moisture, its power of conducting off this vapour will be proportionably diminished, and that an accumulation of fluid may thus take place in the lungs; on the other hand, we may suppose the air to be so dry as to have an increased capacity for moisture, and to carry off the expired vapour with preternatural avidity; in either of these cases, the excretions from the lungs will be materially influenced, whether to the benefit or disadvantage of the patient will depend, in each particular instance, upon the nature of the disease under which he suffers. I have known a person who could breathe with more freedom in the thick fogs of the metropolis than in the pure air of a mountainous region, and it would not be difficult to adduce many examples in illustration of a diametrically opposite constitution of the pulmonary organs.

From the same cause we may frequently observe remarkable changes 106occur in the character of a cough, at the breaking up of a frost; in some cases the expectoration will be checked, and in others promoted by a sudden change from a dry to a moist atmosphere. Can a more instructive illustration be offered of that important fact, which I have been labouring in every page to impress upon the mind of the young practitioner, that, remedies are only relative agents?

In the course of considerable experience in the treatment of pulmonary complaints, and in the influence of climate and seasons upon them, I have repeatedly observed the rapid transition from moisture to dryness to occasion very remarkable effects upon the disease; and I much question whether an attention to such a condition of the atmosphere does not deserve as much consideration in the election of a suitable place of residence for such invalids, as the more obvious circumstance of temperature. I have been long in the habit of recommending to persons confined in artificially warmed apartments, to evaporate a certain portion of water, whenever the external air has become excessively dry by the prevalence of the north-east winds, which so frequently infest this island during the months of Spring; and the most marked advantage has attended the practice. But in such cases the practitioner must ever be guided by the symptoms of each particular case; it would be worse than useless to lay down any general precept for his guidance. We cannot then be surprised that such a difference of opinion should exist amongst practitioners of equal eminence, respecting the influence of a marine atmosphere; some advocating its advantages to the pulmonary invalid, and others maintaining with equal confidence the injurious tendency of such localities; each party appeals to experience in justification of his opinion, and with equal candour and justice; but the cases from the results of which the medical inference has been drawn, however parallel they may have appeared, differed in those essential points to which we have alluded, and upon which the question of climate would seem to turn. There is another circumstance connected with the subject of atmospheric moisture which it is also essential to remember,—that the air gains a considerable increase in its power of conducting caloric, by becoming saturated with aqueous vapour; thus, when a thaw takes place, and the thermometer rises a few degrees above 32°, the air, instead of impressing us with the sensation of increased temperature, actually appears much colder.

SIALOGOGUES;

Substances which increase the salivary^[166] discharge. This class comprehends two orders of medicines, viz.

1st. Those which increase the salivary excretion by external application to the secreting vessels, by mastication, as the following acrimonious and pungent substances, Anthemis Pyrethrum; Colchearia Armoracia; Daphne Mezereum; Nicotiana Tabacum, &c.

2nd. Those whose internal exhibition affects these organs through the medium of the circulation, of which Mercury is the only true example; for all the preparations of this metal, when administered in certain quantities, produce salivation.

The acrid Sialogogues, or Masticatories, by stimulating the excretory 107ducts, and increasing the secretion of saliva, sometimes relieve the pain of tooth-ache, and are commonly resorted to for that purpose; they are besides supposed capable of relieving other congestions, or inflammatory dispositions, in remote parts of the head, by the derivation they occasion from the neighbouring vessels, especially the branches of the external carotid.

Mercury, in its metallic state,^[167] is perfectly inert, and does not exert any influence whatever upon the living body: this fact is sufficient, if any serious refutation were necessary, to overturn the theory which attributes its sialogogue property to the gravity of its particles, by which “it is disposed to retain the direct line in which it is propelled from the heart, and is therefore more certainly determined to the vessels of the head.” It has been also supposed to act by diminishing the lentor of the blood, and disposing it to pass more easily into the salivary glands, so as to increase their secretion: equally gratuitous and improbable are the chemical hypothesis which have been offered to explain this curious and singular property; Dr. Cullen endeavoured to solve the problem, by supposing that “Mercury has a particular disposition to unite with ammoniacal salts, and that such salts are disposed to pass off by the salivary glands more copiously than by any other excretion.” Dr. Murray, however, very justly remarks that mercury has not any peculiar tendency of this kind; and that if it had, these salts are not more abundant in the saliva, than in some other secretions. Dr. Murray then proceeds to submit a theory which he considers better calculated to explain the phenomenon; he observes, that the urine appears more peculiarly designed to convey matter which has been received into the circulating mass, but which is still excrementitious, from the system. To pass, however, with this fluid, it is necessary that the matter conveyed should be soluble in it; and when it is so, we can discover it in the secretion by chemical tests. If there is any property connected with it, therefore, which shall prevent this solubility, it probably will prevent the substance from being secreted. Now, the phosphoric acid, abundant in urine, must in this mode counteract the secretion of mercury in any form of preparation, by forming with it a compound, insoluble, and to which the slight excess of acid cannot communicate solubility; the mercury, therefore, existing in the circulating mass, when brought in the course of the circulation to the secreting vessels of the kidneys, will not pass through their whole course; but if conveyed so far as to be combined with phosphoric acid, will, from this combination, be incapable of being conveyed onwards, and will therefore be retained in the composition of that part of the blood which does not enter into the secretion, but returns into the circulation. It must be discharged by some other emunctory; a portion of it appears, from some facts, to pass off by the insensible perspiration; but the tenuity of this secretion, if the term may be employed, must be unfavourable to this mode of discharge. The salivary secretion is one by which it may be more easily transmitted; and this transmission may even be facilitated by the affinity exerted to the Oxide of Mercury by the Muriatic Acid, the Soda, and Ammonia, which are the chief saline ingredients in saliva; for it deserves to be remarked that triple compounds of these substances are, to a certain extent, soluble in water; and if the Mercury 108is thus secreted, it will of course stimulate the secreting vessels through which it passes, and increase the discharge.

Sir Gilbert Blane^[168] has lately advanced another hypothesis to account for the effects of mercury as a sialogogue; he considers the salivary glands as one of the outlets for the ramenta of the bones, for by analysing the saliva we discover the principles of which they consist; indeed the osseous matter not unfrequently concretes on the teeth, and sometimes on the salivary ducts, in the form of what is called Tartar: “does not this fact,” says Sir Gilbert Blane, “in some measure account for these glands being the parts upon which determination is made by the operation of mercury, which consists in exciting an active absorption of solid parts, as I have elsewhere observed?”^[169]

But do not the kidneys, and other excretory glands also furnish outlets, through which the detritus of the body is eliminated. How does it happen, therefore, that the kidneys are not as equally affected as the salivary glands by the action of mercury? In the present state of our knowledge it will be more prudent to rest on the phenomenon as an ultimate fact, than in attempting to ascend higher in the scale of causes, to involve ourselves in impenetrable darkness.

During the prevalence of the theory which attributed to Nitric acid all the antisyphilitic powers of mercury, it was even maintained that this acid also excited ptyalism; experience however has disproved the effects thus attributed to it, and no one attempts to support its pretensions, as a sialogogue, except indeed as it may perchance, by its acrid qualities, influence the excretory ducts of the glands, externally, in the act of being swallowed.

It has very lately been stated by Dr. Macleod,^[170] that the Hydro-cyanic acid occasionally produces soreness of the gums, and a disposition to ptyalism; this, if true, is a very remarkable fact, and well deserves attentive consideration.

Some theorists may, perhaps, be inclined to consider certain Nauseating Medicines as possessing sialogogue properties. It cannot be denied that an increased discharge of saliva will take place during the operation of such remedies, but it is very transient, and can never be rendered available to any therapeutic object. I shall however have occasion to refer to this fact hereafter, and to the inference deduced from it by Dr. Eberle, in explanation of the effect of nauseating medicines in promoting the operation of Mercury.

ERRHINES, or STERNUTATORIES:

Substances which, by direct application to the pituitary membrane, occasion a discharge from the nostrils either of a mucous or serous fluid. This class contains several different species, whose operation varies in intensity, as well as in duration.

Errhines have been regarded as useful in consequence of the evacuation they occasion, but in this respect their value has been greatly over-rated; it has been stated, that they diminish the quantity of fluid circulating 109in the neighbouring vessels, and even extend their influence to all the branches of the external carotid; and Dr. Cullen says that he has, apparently from this operation, known head-ache, pain of the ear, and some cases of ophthalmia, cured or relieved by the use of Errhines. There can be no doubt that local stimulants of this kind will frequently remove pain from the head and neighbouring parts, but not merely by occasioning vascular depletion, as Dr. Cullen supposed, but by a stimulant operation conveyed through the medium of nervous communication, or contiguous sympathy.

Dr. Cullen has moreover supposed, that these substances may be useful in preventing apoplexy or palsy. Morgagni^[171] however relates a case in which sneezing induced a fatal attack of this disease; and Van Swieten^[172] has satisfactorily shewn, that continued paroxysms of sneezing tend to load the vessels of the head with blood; for the violent contraction of the chest impedes, for a time, the passage of the blood through the lungs, and therefore obstructs the return of the venous blood from the brain, the vessels of which are in consequence greatly distended; the face therefore reddens and becomes turgid, the eyes are suffused with water, and appear full and distended. Its occasional dangerous violence is said to have given origin to the benediction so universally bestowed on those who sneeze.^[173]

It has been a subject of popular inquiry, how far the habitual use of Snuff may prove beneficial or injurious; and whether the habit, when once fully established, can be discontinued with impunity? It may be remarked that Snuff, by habitual use, soon ceases to produce the effect of an Errhine, for which reason its discontinuance cannot, generally, be regarded as likely to be attended with any danger; in those cases, however, in which the discharge is perpetuated, a contrary judgment should be pronounced, for all artificial discharges become constitutional by long continuance, and can therefore be seldom checked with impunity. Dr. Cullen states, from experience, that “whenever the nasal discharge has been considerable, the laying aside the custom of taking snuff has been productive of evil.”

EPISPASTICS. Vesicatories. Blisters.

External applications to the skin, which produce a serous or puriform discharge, by previously exciting a high state of inflammation.

When these agents act so mildly as merely to excite inflammation, without occasioning the effusion of serum, they are denominated Rubefacients.

Various substances have at different times, been proposed for the accomplishment of this object,—such as Nitric Acid, Boiling Water, Strong Acetic Acid, Tartarized Antimony, &c. It is, however, generally admitted, that no substance ever employed equals in efficacy, or certainty, the Cantharis Vesicatoria, the common blistering, or Spanish fly; and whose effects may serve to illustrate the modus operandi of this class of remedies.

110By the application of a Blister, the extreme blood vessels are excited into increased action, by which inflammation is occasioned, and the exhalants made to pour out a thin serous fluid which separates the cuticle from the true skin, and forms a vesicle or blister.

From this simple view of the subject it will appear evident, that blisters may produce their salutary effects by several different modes of operation; by a just estimate of which the practitioner will be enabled to reconcile the discordant opinions which have been delivered upon the subject, and to employ these agents with greater satisfaction and advantage.

Blisters may act—

1. As Derivatives, i. e. by producing a derivation of the circulation from the inflamed and engorged vessels of the neighbouring organs to the blistered surface. This mode of operation was long overlooked by the physicians, who ascribed all the beneficial effects of a blister to the evacuation which it produced, while the humoral pathologist, moreover, considered the matter so discharged to be of a morbific nature. That such agents owe their salutary tendency to causes independent of their powers as evacuants, is at once rendered evident by the relief which they afford, when used only as Rubefacients.

2. As Evacuants—by occasioning an effusion of Fluids. In this case the vesicated part may be considered in the light of a new excretory organ, the formation of which requires the establishment of a new current or determination of blood; so long as the discharge continues, so long will there be an especial demand of blood in the blistered part, and a consequent derivation of the circulation from the inflamed and engorged vessels of the neighbouring organs.^[174] The nature of the fluid effused is at first serous, but after some time it becomes purulent, and this stage of its operation must be considered as, by far, the most beneficial; hence the great advantages derived from a “perpetual blister.”

3. As General Stimulants, by raising the vigour of the circulation.^[175] That Blisters have such a tendency there exist too many proofs to allow us to doubt. Hence in fevers they frequently prove valuable auxiliaries, but since the application of any stimulus, in such diseases, must be regulated by the degree of excitement, it is evident that they can only be made with success in particular stages; this simple fact will at once explain the cause of that want of unanimity in Physicians with respect to the value of blisters in febrile diseases. Rush considered that there was one particular period, in the course of a continued fever, intermediate between its stage of high excitement and the appearance of a collapse, in which blisters will generally produce unequivocal good effects, and to this he gave the name of the Blistering point.

4. As Antispasmodics.—Relieving pain through the medium of Contiguous Sympathy. This effect would frequently appear to be independent of the operations above enumerated; a similar principle seems to exist 111with regard to the pain excited by blisters, which may also be applied to the explanation of the advantages derived from them in several diseases. It has long been remarked that, by exciting one pain we may often relieve another, and hence blisters afford relief in tooth-ache, and other painful affections. Epilepsy and Hysteria, arising from irritation, have been removed by such applications, apparently from their exciting powers.

It remains for us to make a few observations upon the abuse of these remedies, for, notwithstanding the popular adage that “Blisters are always safe things,” that “if they do no good, they can do no harm,” they will be found, like all other potent applications, capable of producing much mischief when directed by unskilful hands. In stages of high vascular excitement in the pulmonary organs, blisters have increased the irritation they were designed to allay, and in some cases have promoted a tendency to effusion; in the treatment of acute Hydrocephalus the common practice of blistering the head appears very questionable, and has too often, I am well persuaded, accelerated the fatal termination, by increasing the disposition to serous effusion.

ISSUES (Fonticuli) and Setons (Setacea^[176]).

The effects of these processes bear a strong analogy to those which are produced by Vesicatories; they are, however, more permanent, and are on that account better adapted to the relief of those chronic affections which would seem to require a remedy of long continued influence. In pulmonary affections, for instance, a seton in the side is frequently attended with very considerable benefit. The popular belief in humoral pathology, which continues to influence the mass of mankind, has perhaps assigned to these remedies a greater share of credit than that to which they are really entitled, but it must still be acknowledged that when an ulcer having existed a great length of time, is healed or dried up, or any constitutional discharge is suddenly checked, the health may become affected. In such cases the establishing a discharge by means of an Issue is undoubtedly a safe, and often a beneficial operation.

III. OF CHEMICAL REMEDIES.

There is no principle in physiology better established than that which considers vitality as a power engaged in continual conflict with the physical, chemical, and mechanical laws, to which every species of inanimate matter is invariably subject. Every phenomenon of the living body might be advanced in illustration and support of this general position. The animal machine is constantly surrounded and assailed by agents, whose elective attractions for the principles of which it consists, are so numerous and energetic, that its decomposition would inevitably and speedily result, were not the adhesion of its molecules maintained by the conservative influence of a superior power. The compositions and decompositions which manifest themselves in the elaborate operations of chylification, 112sanguification, and secretion, are carried on by agencies totally distinct from those which govern the combinations of inert matter, and must be investigated upon principles essentially different. How then, it may be asked, can a medicinal substance be brought to act chemically upon the living body? Notwithstanding the general proposition, that the animal processes to which we have alluded, are governed by laws peculiar to life, yet it must be admitted that such processes are occasionally influenced,^[177] modified, and controlled by powers strictly chemical in their operation; although in some cases it will be seen that such effects afford only apparent exceptions to the general law: for several of the remedies whose operations have been regarded as purely chemical, exert their influence on parts which cannot be strictly considered under the control of the living principle; of which Antacids, and certain Antidotes and Antiseptics, to be hereafter explained, may be considered as examples: in like manner will cataplasms of acetic acid hasten the exfoliation of carious bone; a practice which has lately been employed with much success in the Infirmary at Gloucester. Upon the same principle alkaline applications may be made to dissolve coagulated blood; suppose, for the sake of illustration, that the bladder should become filled with coagulum through hemorrhage from the prostate gland, and that the most serious consequences were to be apprehended from the distention; in such an emergency, a dilute and tepid solution of potass, if injected through the catheter, might prove eminently serviceable; although such a practice would require the utmost skill for its safe direction, since the removal of the plug, thus afforded by Nature to the bleeding vessel, might be followed by an immediate return of active hemorrhage. On the contrary, other agents destroy the vitality of the organ before they can produce any change in the matter of which it is composed, as the action of Escharotics will clearly demonstrate.

Substances which directly diminish the force of the circulation, and reduce the heat of the body, without occasioning any diminution of sensibility or nervous energy.

These remedies may be considered either as external and local, or as internal and general. In the first case, there will not be much difficulty in substantiating their claims to be considered Chemical Agents, but in the latter case, the theory of their operation is unsatisfactory and obscure; and even the facts which are adduced to establish the existence of such a class of remedies, are of a very problematical character.

Topical Refrigerants. In the case of external inflammation, refrigeration may be produced by the application of cold substances, such as water, ice, or certain saline solutions, or by the abstraction of heat by means of evaporation, which is very effectually accomplished by the use of lotions composed of spirit or ether. By these methods we are capable of directly diminishing the activity of the vessels of the part; thus, in burns and scalds, the pain is instantly relieved, and the inflammation effectually reduced.

Internal Refrigerants. There are certain saline substances which, by undergoing a rapid solution, and acquiring an increased capacity for caloric, produce a diminution of temperature, and if this takes place in the stomach, the sensation of cold which it will produce is equivalent to a partial abstraction of stimulus; which, being extended by sympathy to the heart, occasions a transient reduction in the force of the circulation, and by this, or by a similar sympathetic affection, causes a sensation of cold over the whole body; in this manner Dr. Murray explains the refrigerant operation of nitre, which after all is of a very doubtful nature. We shall perhaps not feel much difficulty in accepting this theory, and in allowing that general refrigerant effects may be temporarily produced, by occasioning an impression of cold upon the stomach. The theory which is proposed to explain the refrigerant operation of vegetable acids and certain other substances, and which we have now to consider, is derived from those chemical views respecting animal heat, in which the consumption of oxygen in the act of respiration is considered the principal source. Dr. Murray,^[178] who has given a luminous exposition of this theory, says “it is established by numerous experiments and observations, that the quantity of oxygen consumed in the lungs is materially influenced by the nature of the ingesta received into the stomach. When the food and drink are composed of substances which contain a small proportion of oxygen, it is known that the consumption of oxygen in the lungs is increased, and this even in a short time after the aliment has been received; thus Mr. Spalding, the celebrated diver, observed, that whenever he used a diet of animal food, or drank spirituous liquors, he consumed in a much shorter time the oxygen of the atmospheric air in his diving-bell; and therefore he had learned from experience to confine himself to a vegetable diet, and to water for drink, when following his profession.”^[179] During digestion 114too, it was established by the experiments of Lavoisier and Seguin, that a larger proportion of oxygen than usual is consumed.

But it is known, that the animal temperature is derived from the consumption of oxygen gas by respiration; and, that an increase in that consumption will occasion a greater evolution of caloric in the system, and consequently an increase of temperature in the body, while a diminution in the consumption of oxygen will have an opposite effect. If, then, when the temperature of the body is morbidly increased, we introduce into the stomach substances containing a large proportion of oxygen, especially in a loose state of combination, we may succeed in reducing the general temperature. This we accomplish in part by a vegetable diet, but still more effectually by the free use of the Acids. The vegetable acids in particular, which are found by experience to be the best refrigerants, are readily acted upon by the digestive powers, and assimilated with the food; and as the large quantity of oxygen which they contain is already in a concrete state, little sensible heat can be produced by the combination of that element with the other principles of the food. The nutritious matter which is received into the blood, containing thus a larger proportion of oxygen than usual, will be disposed to abstract less of it from the air in the lungs, and consequently less caloric will be evolved; the temperature of the body will be reduced; and this, again operating as a reduction of stimulus, will lessen the number and force of the contractions of the heart.

Such is the philosophical web which chemical ingenuity has wove for us,—the device is beautiful, but the fabric will be found too frail to endure the touch. The experiments of Dr. Crawford, in proof of the chemical origin of animal heat, are highly ingenious and plausible, but it is now generally admitted that the temperature of animals depends upon the living principle^[180] which animates them, and that although the absorption of oxygen, in the act of respiration, may directly contribute something to its production, yet that its chief action is that of serving as a stimulus to the living power in generating it; for, as Sir Gilbert Blane^[181] remarks, oxygen plays an interesting and active part as an exciting power throughout all nature, both animate and inanimate. If the heat of the body depended on respiration alone, any one might, by a voluntary effort of quick, deep, and prolonged respiration, increase the temperature of his body at will; the effect also of the emotions of the mind, in generating both heat and cold, adds Sir Gilbert, is proof sufficient of temperature depending on a vital, and not on a chemical cause.

ANTACIDS:

Remedies which obviate acidity in the stomach, by combining with the acid, and neutralizing it.

This is the most decided instance of chemical action which occurs in the history of medicinal operations. We have an acid whose presence excites morbid symptoms in the primæ viæ, and these are immediately removed by the administration of any one of those substances which are capable of forming a natural compound with the acid in question, out of the body, and the same proportions are required in both cases for saturation. 115If a carbonated alkali be employed, the same disengagement of carbonic acid takes place in the stomach as would occur in the laboratory, and a new compound is produced, whose operation varies according to the chemical nature of the substance employed; thus, the salt which magnesia forms with the acid in the stomach proves slightly purgative, while that which lime produces under similar circumstances is distinguished by an opposite property.

ANTILITHICS and LITHONTHRYPTICS.

Antilithics^[182] are remedies which have the power of preventing the formation of those mechanical deposites from the urine, which give origin to calculous concretions; and may belong either to the class of Vital, or Chemical Agents.

Lithonthryptics^[183] are those medicines which, by a chemical operation, are capable of dissolving calculous concretions.

It has been already shewn, while treating the subject of Diuretics, that certain substances, when internally administered, are capable of passing the barriers of digestion, and of entering the circulation; and that, moreover, these bodies may be again separated by the secretory vessels of the kidneys, and be ejected from the body in the urine. It cannot therefore be contended, that the urinary calculus is placed beyond the sphere of direct medicinal influence, nor can any argument, founded upon the alleged incompatibility of chemical and vital action, be fairly maintained in this case; for the urinary calculus, as well as the urine itself,^[184] may very justly be considered as extraneous to the living body. The existence of such a class of remedies as that of Lithonthryptics being thus established, we have to consider the mode and possible extent of their operation in the different varieties of the disease, which they are thus calculated to palliate or cure. In entering upon this inquiry, it is not my intention to prosecute the subject farther than may be necessary to explain the modus operandi of the remedies in question, and in conformity with the object and plan of this work, to establish some general principles that are to direct us in their election, combination, and administration; for farther details the practitioner must consult the systematic treatises of Prout^[185] and Marcet,^[186] and the very able papers of Mr. Brande,^[187] and Dr. Wilson Philip.^[188]

The urine may be considered as one of the most heterogeneous of the animal fluids;^[189] and since a knowledge of its composition, and that of the 116morbid changes of which it is susceptible, must constitute the basis of all our knowledge respecting the formation and cure of calculous affections, the following results of an elaborate analysis by Berzelius, are submitted with a view to elucidate our pathological researches.

Besides the above ingredients, which appear to be essential to healthy urine, Dr. Prout observes that in different diseases it may contain Albumen, Fibrin, and the red particles of the blood; Nitric acid; various acids, which are found to be modifications of the Lithic; Oxalic acid; Benzoic acid; Carbonic acid;^[190] Xanthic Oxide; Cystic Oxide; Sugar; Bile; and Pus.

It will be necessary in this place to make a few observations upon the nature and habitudes of those principles, which are more immediately active in the production of calculi—

1. Urea is a principle peculiar to urine, and must be regarded as a result of the action of the kidneys upon some of the constituents of the blood, perhaps, as Dr. Prout suggests, upon its albuminous matter. For a long time it was regarded as the peculiar principle upon which the colour and other sensible qualities of the urine depended; Berzelius however has corrected this fallacy, and considers that the Lactic acid, and its accompanying animal matters, are the bodies which impart to this fluid the characteristic smell and colour which distinguish it.^[191]

1172. Lithic, or Uric^[192] Acid. As this principle is not found in the blood, but is constantly present in healthy urine, it follows that it must be generated by the action of the kidneys. M. Majendie^[193] has lately endeavoured to prove that its secretion depends upon the Azote received in alimentary substances, and for the following reasons, viz. 1. Azote is a component part of Lithic Acid^[194]—2. Those persons who use a large portion of animal food, and fermented liquors, are liable to calculous disorders—3. When animals are confined to food which contains no Azote, no Lithic acid is formed—but of this anon.—Berzelius and other animal chemists have supposed that this acid exists in urine in a free state; but Dr. Prout, whose arguments appear very satisfactory and decisive, is of opinion that it is always in combination with ammonia (Lithate of Ammonia), from which however it is very easily separated by the addition of any acid, even the carbonic, in the form of a red powder. It moreover appears to be susceptible of several important modifications, with which it behoves the pathologist to be acquainted; the profession is greatly indebted to the ingenuity and industry of Dr. Prout for some very essential additions to our knowledge, respecting the habitudes of Lithic acid with different bodies.

Erythric Acid. When nitric acid diluted with about an equal bulk of water, is poured upon pure lithic acid, and a moderate heat is applied, an effervescence takes place, and the lithic acid is dissolved; if we then concentrate this solution by a gentle evaporation, we obtain transparent colourless crystals, which have been found to constitute a peculiar acid, to which M. Brugnatelli has given the name of Erythric acid.

Purpuric Acid. Dr. Prout has discovered that if into a strong solution of the above crystals in water, whilst boiling hot, we carefully drop some pure ammonia, the solution acquires a beautiful purple^[195] colour, and crystals of purpurate of ammonia speedily begin to form and subside. If these crystals are treated by means 118of potass and sulphuric acid, pure Purpuric acid is obtained in the form of a yellowish, or cream-coloured powder.

3. The Phosphates. As the Phosphoric acid and its compounds perform an important part in the generation of calculi, their origin^[196] and history demand particular attention from the chemist. The Phosphoric acid frequently exists in the urine in a free state, when it would appear to act, like any other acid, as a precipitant of the Lithic acid; this however is not the circumstance that renders its presence formidable; it is to the abundance of its compounds that we are to look for mischief. In healthy urine the phosphoric acid appears to exist in union with soda and ammonia, and partly with lime and magnesia; the latter salts being retained in solution by an excess of acid; but the proportion of these bodies is liable to considerable variation.^[197]

Having thus briefly noticed those particular points in the chemistry of the subject with which the therapeutic principles are more immediately connected, we shall be better prepared to examine and appreciate the several plans of treatment which have been proposed for the prevention, cure, or palliation of calculous disorders; and here the subject naturally divides itself into two parts; the one comprehending the modus operandi of Antilithics, or those remedies which prevent or correct the calculous diathesis; the other, explaining the solvent action of Lithonthryptics over concretions already formed.

The line of demarcation by which healthy and morbid urine are separated, is so slight that it is difficult to define its limits; nor would the circumstance appear to be materially important, for the boundary is daily exceeded, not only with impunity, but even without our consciousness of the event; and Dr. Prout has accordingly denominated such occasional deviations, the “Sediments of Health.”

The same enlightened author considers that mechanical deposites from 119the urine, although composed of the same general ingredients, may, in a pathological point of view, be conveniently divided into three classes, viz. Pulverulent or Amorphous Sediments; 2. Crystalline Sediments, usually denominated gravel; and 3. Solid Concretions, or calculi formed by the aggregation of these latter sediments. The first of these may be passed over, as unconnected with the present subject; the latter however constitutes an essential object of research; for a complete acquaintance with the chemical history of calculi can alone furnish the true indications of cure.

Scheele,^[198] with whom the inquiry originated, conceived that every calculus consisted of a peculiar concrete acid, soluble in alkaline lixivia, and which Morveau denominated the Lithic Acid; but the subsequent researches of Fourcroy, Vauquelin, Wollaston, Pearson, Henry, Brande, Marcet, and Prout, have demonstrated the existence of several bodies in the composition of urinary calculi, viz. Lithic Acid; Phosphate of Lime; Ammoniaco-magnesian Phosphate; Oxalate of Lime; Cystic Oxide;^[199] and Xanthic Oxide;^[200] to which may be added an animal cementing ingredient. The varieties of calculi produced by the combination or intermixture of these ingredients, are represented in the following Tabular Arrangement.

121Let us now inquire into the circumstances under which the several substances enumerated in the foregoing table, are found to be deposited; and first of the Lithic acid Diathesis. It has been already stated, that the lithic acid exists in the urine in combination with ammonia, so as to be held in solution under ordinary circumstances; if however any free acid be generated, the lithic acid is immediately precipitated, giving rise to the appearance so well known under the name of red gravel; from this view of the subject the lithic acid deposite must be considered as arising, not from the excess of that substance in the urine, but from a decomposition of the compounds into which it enters by the agency of a free acid. M. Majendie is therefore incorrect in attributing its appearance to the quantity of azote in the ingesta; an opinion which has been very ably controverted by Dr. Philip, in a paper published in the sixth volume of the Medical Transactions. It appears, moreover, that whatever tends to disturb the process of digestion, by favouring the production of acid, may be considered as the exciting cause of the lithic deposites; especially where the cutaneous functions are imperfectly performed; for Dr. Philip is of opinion, that the precipitating acid, in a healthy state of the system, is thrown off by the skin; and he supposes that even when generated in excess, it may be diverted to the surface of the body by merely increasing the insensible perspiration. The medical treatment of the lithic diathesis is thus rendered simple and satisfactory; and if the opinion of Dr. Prout be true, that at least two-thirds of the whole number of calculi originate from lithic acid, the extreme importance of the subject is too apparent to require comment. Remedies, medicinal and dietetic, that are capable of correcting dyspeptic symptoms, such as slight bitters,^[201] will doubtless prove valuable resources; while all those agents which have a tendency to correct and regulate the insensible perspiration, will necessarily fall under the head of anti-lithic remedies. Mr. Copland Hutchison, in a paper which has been published in the Transactions of the Medico-Chirurgical Society, has shewn a comparative rarity of calculous disorders in British seamen. Can the quantity of muriate of soda taken with their food, from its stimulating influence upon the cutaneous functions, be considered as affording a plausible explanation of this fact? The Phosphatic Diathesis seems to be accompanied with considerable derangement of the chylo-poietic viscera, and Dr. Prout very justly remarks, what I have frequently observed, that the stools are extremely unnatural; as the phosphates are retained in solution by an excess of acid, it would appear as if an alkaline principle was occasionally developed, and it is not unreasonable to suppose that this may be sometimes derived from bilious regurgitations;^[202] in some cases, the alkali is derived from the spontaneous decomposition of urine itself, especially where the bladder has lost its governing power,^[203] as 122from some injury^[204] of the spine; or from some local affection of the bladder or prostate gland; wherever the urine undergoes an incipient process of decomposition, ammonia will be generated, and an ammoniaco-magnesian phosphate^[205] be immediately precipitated: hence in cases where the bladder is unable to discharge its contents, this deposite is very apt to take place, as in diseases in the prostate; and this explains the reason why the triple phosphates are so frequently formed in elderly people, who cannot wholly evacuate their bladder.

It will appear evident from these cursory observations, that some varieties of Calculi will be influenced by acids, and others by alkalies, and that the exhibition of such remedies will be liable to palliate, or to aggravate the symptoms, according to the character and composition of the offending calculus, and according to the prevailing diathesis of the patient; as a general rule to direct us in the chemico-medical treatment of these cases, Dr. Marcet states, that “Whenever the lithic acid predominates, the alkalies^[206] are the appropriate remedies, but that when the calcareous or magnesian salts prevail, the acids are to be resorted to.” But if it be asked how we are to discover the nature of the calculous affection, so as to direct the suitable remedy? the reply is obvious—by an examination of the sediment deposited by the recent urine, or by an analysis of the small fragments which are frequently voided with it; the Phosphates subside from the urine as a white, lithic acid, generally, as a red deposit; and since the phosphates are held in solution in the urine by an excess of acid, it is evident that whenever such acidity is diminished by the hand of Nature or art, a white sabulous deposit will ensue; hence, says Mr. Brande, it occurs in the urine of persons who drink soda water, or take magnesia; the remedy of such a deposit, when it takes place habitually, is a course of acidulous medicines; on the contrary, since lithic acid is precipitated by the acids, alkalies are naturally suggested for the prevention of that deposit. In the compound calculi, acids and alkalies may be equally injurious or beneficial, for since these bodies are composed of a variety of ingredients, the action of any one solvent must be partial, and may convert the smooth calculus into a rough and highly irritating body, or vice versa. In the alternating calculi it may be judicious to exhibit these remedies alternately, as the symptoms of the case and the deposit of the urine may indicate. After all, however, the solvent powers of Lithonthryptic remedies must be very limited, and in advanced cases we can never expect to procure more than palliation. With respect to the agency of these different remedies, as Antilithics, I would observe, that while experience bears us out 123in confiding in the production of certain chemical effects from their use, we must not forget that much is to be effected by their judicious administration as vital agents: and it will be hereafter my duty to point out the many advantages that may be obtained, by combining in one formula, medicines which individually belong to each class.

Independent of any chemical effect, alkaline substances are found by daily experience to allay the morbid irritability of the urinary organs in a manner not yet explained; alkalies may also prove generally serviceable in these disorders, by acting immediately upon the digestive organs, for the disposition of forming calculi is always, more or less, accompanied with the indications of deranged digestion; and it is probable that the first link of the series of actions, which cause this disposition, has its origin in the stomach.

The alkaline carbonates are found to answer as effectually as the pure alkalies, and they have the advantage of being less liable to disagree with the stomach. Mr. Hatchett has proposed the carbonate of magnesia, in doses of ℈j to ʒj, as a valuable substitute for alkaline remedies in cases of lithic calculi; but as its insolubility must render its absorption equivocal, the beneficial operation of the substance must principally depend upon its neutralizing any excess of acid in the primæ viæ, and in this way there can be no doubt of its lithonthryptic agency; “but,” says Dr. Marcet, “such is the tendency which the public has to over-rate the utility of a new practice, or to take a mistaken view of its proper application, that there is every reason to believe that the use of magnesia has of late years become a frequent source of evil in calculous complaints.” Lime-water has been also recommended for the purpose of fulfilling the same indications, and as not being liable to produce that irritability of stomach which frequently attends the long continued use of the fixed alkalies; besides which, some chemists have maintained that it exerts a peculiar solvent power over the cementing animal matter of the concretion, and thereby destroys its cohesion.^[207]

Where an acid is indicated, the Muriatic will in my judgment be found as convenient and effectual as any that can be administered. Mr. Brande proposes Cream of Tartar for this purpose; upon this point I differ with him, for this salt, to say the least of it, is questionable in its mode of operation; for although its first impression upon the stomach is that of an acid, the subsequent processes of digestion decompose it, and eliminate its base, which being absorbed acts upon the urinary organs as an alkali. I have seen a white sabulous deposit, consisting of the Phosphates, in the urine of persons after the constant use of Imperial as a beverage, which I am at a loss to explain upon any other principle. Sir Gilbert Blane has also very satisfactorily shewn, that a fixed alkali produces the same effect upon the urinary organs whether it be exhibited alone, or in combination with citric acid; in this latter case the salt undoubtedly undergoes a decomposition in transitu, as I have more fully explained under the consideration of Diuretics, (page 94.) During an alterative course of Lithonthryptic remedies it may be beneficial to interpose occasionally a purgative medicine, but we must not combine it with the lithonthryptic, at least, if we wish this latter medicine to reach the urinary passages; for it is a law which I have already attempted to establish (see page 94), that Catharsis suspends the process of alimentary absorption.

124There remains to be considered another mode of applying a solvent, and which would seem on the first view of the subject to be full of promise,—that of injecting the proposed menstruum into the bladder. Unfortunately, however, the irritable state of this organ will generally preclude the possibility of preserving the menstruum, for a sufficient length of time, in contact with the calculus to accomplish any material solution; nor am I aware that any case, in favour of such a practice, stands recorded. An ingenious and novel application of the powers of Electro-chemistry has been lately^[208] proposed by M M. Prevost and Dumas, as capable of affording means for the solution of the calculus within the bladder; the suggestion is highly plausible, and ought not to be hastily rejected without trial. Could the functions of the part be protected against the influence of so powerful an agent, it is evident that, by a galvanic battery of sufficient intensity, a calculus composed of alkaline or earthy salts might be transferred from the bladder by the simple introduction of a double sound, communicating on one hand with the calculus, and, on the other, with two vessels filled with water, in which are plunged the opposite poles of a galvanic apparatus.^[209] This arrangement would transfer the acid constituents into the vessel connected with the positive end, and the bases into that of the negative end. So far, however, as the experiments have hitherto been carried, this degree of galvanic operation would seem to excite too much irritation in the bladder to be admissible; but it still offers a resource of an apparently more practicable nature. This consists in giving to the calculus a tendency to crumble from the slightest force; such a friability, in short, as shall render it easily broken into pieces sufficiently small to be evacuated through the urethra, especially by the aid of dilating that passage, an operation upon which much has lately been said and written. A fusible calculus from the human subject was submitted to the action of a pile, consisting of 120 pairs of plates, for twelve hours in succession. The platinum wires, constituting the poles, were placed in contact with the calculus, about six or eight lines distant from each other, and the whole plunged in a vessel filled with pure water. During the galvanic action, the bases and phosphoric acid first arrived at their respective poles, then re-entered into combination, when the salt thus reformed was precipitated in the state of powder. The calculus weighed 92 grains before the experiment, and was reduced at its termination to 80. The process being continued, at the end of sixteen hours it presented a mass of such friable texture as to be reduced into small crystalline particles by the slightest pressure; the largest of which did not exceed the size of a lentil, so that it might have easily passed through the urethra.

In order to ascertain how far this decomposition could be effected in the living body, the ingenious experimentalists selected a dog of rather large size, into whose bladder they introduced a fusible calculus attached to a sound, and between two conductors of platinum; the bladder was next distended by injecting tepid water, and the apparatus subjected to galvanic influence. After a little struggling, the animal became calm, and was subjected to the operation during an hour. On removing the sound, the calculus shewed unequivocal marks of decomposition. The same process was repeated, night and morning, during six days, when the friability of 125the calculus rendered it impossible to continue the experiment. It had lost weight in the same proportion as in the preceding trial. The bladder, which was afterwards examined, exhibited no appearance of injury or disease.^[210] The authors assert that this organ does not suffer any inconvenience from this more moderate degree of galvanic action, and suggest, as a proof of the mildness of its influence, that we should immerse the tongue in a vessel filled with water, in which a calculus is undergoing decomposition, and it will be found that the tongue, which is far more sensible than the bladder, will scarcely perceive the galvanic action, even when decomposition is going on briskly. The authors add, that this process cannot offer any advantage for the removal of those calculi which consist wholly of Uric acid, or which contain a large proportion of it.^[211]

ANTIDOTES.

Medicines which are capable of preventing the ill effects of a poison; or, of counteracting its fatal virulence.

There is perhaps no subject upon which the credulity of mankind has been so extravagantly exercised as on that of Poisons; nor is there, certainly, any class of remedies whose history has suffered so many vicissitudes from the caprice of hypothesis, as that of Antidotes.^[212]

It is not my intention, on the present occasion,^[213] to enumerate the many extraordinary virtues^[214] which credulity has, at different times, assigned to such medicines; nor shall I consume the time of the reader by attempting to expose the absurdity of those fearful powers with which ignorance, terror, and imposture, have invested certain poisons,—a subtlety so extreme as to defeat the most skilful caution, and a virulence so manageable as to be capable of the most accurate graduation; so that while the former attribute was believed to ensure their deadly operation, although exerted through the most secret and least suspicious medium, as that of gloves,^[215] tapers, or letters, the latter was said to enable the accomplished 126assassin to measure the allotted moments of his victim with the nicest precision, and to occasion his death at any period that might best answer the objects of the assassination.^[216]

The abandonment of such notions may be considered as one among the many advantages which have arisen to medicine, from the cultivation of physiology.

Without farther introduction, I shall proceed to the main object of this work, and inquire how far a chemical agent may be capable of neutralizing, or of decomposing, a poisonous substance in the human body; and endeavour to ascertain the degree of confidence to which it may in each particular case be entitled; equally important is it to learn, whether certain vital agents may not be serviceable in cases of poisoning, either by promoting the elimination of the poison, or by producing a state of the system best calculated to resist its deleterious operation.

It may be safely asserted that we possess very few true antidotes; for although several of the mineral poisons may be neutralized or decomposed by various reagents, yet their destructive action is generally so rapid, that the mischief is effected before any chemical changes can avail; and, in other cases, the substances resulting from the chemical action, are as poisonous as the original ingredients, as in the case of the decomposition of Corrosive Sublimate, by the alkalies and earths, when the precipitated oxide is as virulent as the original salt; while, under certain circumstances, I suspect that the vital powers of the stomach are in direct opposition to those changes and decompositions which so readily, and so uniformly, take place in our laboratories. To vital agents then, the practitioner must principally look for succour; but before we can establish any general rules for the treatment of poisoning, it is essential to distinguish between the different modes in which poisonous substances produce their effects, or at least to determine the parts of the living system through which they act; for it will be found, that each poison has its own modus operandi, from which alone can be derived the particular indications of cure.

The hypotheses devised by the ancient physicians, to account for the destructive powers of these substances, were principally derived from mechanical notions respecting the supposed form of their particles, which they imagined capable of lacerating and disuniting the animal fibres by the sharpness of their spiculæ;^[217] it is however, now satisfactorily established 127that the action of a poison in the human stomach is very rarely, if ever, mechanical; sometimes chemical; but for the most part vital in its operation.

Each of the three kingdoms of Nature furnishes a number of poisons, the investigation of whose chemical properties and physiological actions, and that of the symptoms to which their administration gives rise, the lesions of structure which they occasion, and of the medical treatment which they require, constitutes an elaborate branch of science designated by the term Toxicology, and of which I have more fully treated in my work on Medical Jurisprudence.

Poisons differ materially from each other, not only with respect to the modes in which they produce their effects in relation to the several vital organs, but with respect to their application; some of those, for instance, which, if introduced into a wound, are speedily fatal, may be taken into the stomach with complete impunity, as in the instance of the venom of the viper and other snakes, which appears to exert no influence on the stomach; others, on the contrary, display their deleterious action on the stomach alone, such as caustic acids, and alkalies, corrosive sublimate, and some chemical poisons; while others, again, are equally destructive whether applied to the inner surface of the stomach, or to the lower intestines, in the form of clyster, or even to the mucous membrane of the mouth or nose; to the eye; to the vagina and orifice of the uterus, or to an abraded portion of the skin. There is, moreover, a class of substances which may be termed Aerial poisons, for they may exist in the state of gas, or be held dissolved in the atmosphere, and be received by respiration, or by the mucous membranes of the nose and throat; the saliva may also thus become the medium for transferring various subtile poisons from the atmosphere to the animal body; this is well illustrated by the fact of the transfer of metallic influence, as related in the case of a gentleman in perfect health who became salivated in consequence of sitting for one hour by the side of a person who was in a state of mercurial ptyalism, in order to give him a lesson in botany.

It also deserves notice, that a poison acts with different degrees of force and celerity in different parts of the same tissue; its absorption, for instance, would appear to be energetic in proportion to the number of veins,^[218] 128although several apparent exceptions to this law might be adduced, and it is evident that the plethoric state of the part with respect to its blood-vessels has a considerable share in modifying the effects; this observation, however, has no relation to those poisons which operate on the system through the sympathetic communication of the nerves; Mr. Brodie, for instance, found that the poison of bitter almonds acted more speedily when applied to the tongue than when injected into the intestine, though the latter presents a much better absorbing surface.

Foderé, in the fourth volume of his Medicine Legale, arranges poisons according to their action on the living system, and which, with a slight alteration in the order of the classes, has been adopted by Orfila, and most other writers on Toxicology. Poisons are thus reduced into six classes: viz. 1. Corrosive or Escharotic, as the Preparations of Mercury, Arsenic, Antimony, Copper, Tin, Zinc, Silver, Gold, and Bismuth; the concentrated Acids, and caustic Alkalies, and Earths; Cantharides; glass and enamel powder; diamond dust.^[219] 2. Astringent Poisons, of which the preparations of Lead constitute the only species. 3. Acrid or Rubefacient Poisons, which, with a few exceptions, are furnished by the vegetable kingdom, as certain drastic purgatives, Hellebore, Euphorbium, &c. 4. Narcotic Poisons, Opium, Henbane, the Cherry-laurel, Stramonium, &c. 5. Narcotico-Acrid, embracing such articles as produce the united effects of the two former, and which constitute some of the most deadly poisons, as the Ticunas, Nux-vomica, Belladonna, Tobacco, Hemlock, Digitalis, &c. 6. Septic Poisons, contagious miasmata, putrid exhalations from animal matter, Sulphuretted Hydrogen, the venom of the viper, &c.

The value of this classification has been very justly stated to consist in its combining to a certain degree, the advantages of a pathological arrangement with those of one founded on the basis of Natural History; for, while it is strictly pathological, it at the same time distributes the different poisons, with some few and unimportant exceptions, in an order corresponding with that of their natural history. The First two classes, for instance, present us with substances of a mineral origin; the Third 129and Fourth, with those which are chiefly of a vegetable nature; and the Sixth, with objects principally belonging to the animal kingdom. The importance of acknowledging a division, which has a reference to the organic and inorganic kingdoms of Nature, is considerable in a chemical point of view; for in enumerating the various experiments to be instituted for the detection of poisons, we are thus enabled to bring together a connected series of processes, nearly allied to, intimately connected with, and in some respects mutually dependent upon, each other. At the same time it must be acknowledged, that this classification has many defects and some fallacies. In the first place, it has little or no reference to the enlarged views of the modern physiologist, respecting the “modus operandi” of Poisons; nor indeed is its construction susceptible of such modifications and improvements, as can ever render its degree of perfection progressive with the advancement of science. In the next place, the classes are in many particulars ill defined, and indistinctly, if not erroneously, divided. How questionable, for instance, are the boundaries which separate Corrosive from Acrid poisons? the respective species, even, of each class are, in many cases, less allied to each other, than are the great divisions to which they are subordinate. As an exemplification of this fact we have only to compare the physiological actions of Arsenic and Corrosive Sublimate, both of which are arranged under the class of Corrosive Poisons. The former of these substances undoubtedly occasions death by being absorbed, and thus acting as a vital agent; the latter, by its local action, as a caustic on the textures with which it immediately comes into contact. In the same manner, if we examine the individual actions of the different species composing the class of “Acrid Poisons,” we shall discover the same want of uniformity; thus, the Spurge Flax, and the Iatropa Curcas, act by occasioning a local inflammation, while the Hellebore, being rapidly absorbed, exerts a fatal action on the nervous system, and produces only a very slight inflammation. The class of Narcotic Poisons is certainly more absolute in its definition, and more uniform in its physiological affinities, and therefore less objectionable than the divisions to which we have just alluded; but the propriety of the class “Narcotico-Acrid” is by no means equally unexceptionable; indeed Orfila himself questions it, “because the narcotic or sedative effects only follow the previous excitement.” Some of the poisons of this division also are rapidly absorbed, and act, through the medium of the circulation, on the nervous system, without producing any local inflammation; while others, on the contrary, merely act upon the extremities of the nerves, with which they come in contact, and, without being absorbed, occasion death by a species of sympathetic action.

These few objections, and many more might be urged, are sufficient to demonstrate the imperfection of the classification under consideration, and which must render it wholly unavailable to the physician in the treatment of cases of poisoning, who must derive his plan of cure from the physiological action of the substance against which he has to contend; thus, for instance, Arsenic and Corrosive Sublimate are both corrosive poisons, but so materially do they differ from each other in their physiological actions that, when swallowed, they will require for the preservation of the individual, a very different system of treatment.

For such reasons I have ventured to propose a new arrangement of Poisons, which may furnish the practitioner with a general theorem for the administration of Antidotes.

131The First Class of our arrangement comprehends such poisons as operate, through the medium of the nerves, upon the organs immediately subservient to life; in their application it is obvious that they cannot require to be introduced into the stomach; they may convey their destructive influence by an application to any part duly supplied with nerves, and whose extremities are exposed to their action. It had been long admitted that a poison might occasion death, by acting on the nerves of the stomach and intestines without being absorbed; but to the experimental labours of Mr. Brodie^[222] we are principally indebted for our present correct views of the subject. The class admits of two important divisions, into one comprehending those poisons which destroy the functions of the brain, and into another, including those which direct their influence upon the heart. We shall offer a few observations upon the facts which have suggested such a division, and upon the practical advantages which may attend its adoption.

It was observed by Bichât, and the observation has been fully confirmed by Brodie, that the influence of the brain is not directly necessary to the action of the heart; and is immediately necessary to life, only because the muscles of respiration owe their action to its influence.^[223] For when the functions of the brain are destroyed, even when the head is removed, the heart continues to contract for some time afterwards, and then ceases only in consequence of the suspension of respiration, which is under the direct influence of the brain. Assuming this as a fact, it will appear evident that certain poisons may, by affecting the brain, so paralyse the muscles of respiration as to occasion death by suffocation, and by such a mode of operation I imagine that those substances, arranged in the former division of my first class, prove mortal. Mr. Brodie accordingly found that, by the administration of a large dose of alcohol to a rabbit, the pupils of its eyes became dilated, the extremities convulsed, and the respiration laborious, and that this latter function was gradually performed at longer and longer intervals, and that it at length entirely ceased. Two minutes after the apparent death of the animal, he opened the thorax, and found the heart acting with moderate force and frequency, circulating dark coloured blood; he then introduced a tube into the trachea, and produced artificial respiration by inflating the lungs, and he found that by these means the action of the heart might be kept up to the natural standard, as in an animal from whom the head is removed. The same phenomena resulted from the injection of two drops of the Essential Oil of Bitter Almonds, diffused in half an ounce of water, into the rectum of a cat; and from the application of the empyreumatic oil of Tobacco to the tongue, and rectum of cats and dogs. Now it is obvious that the functions of the brain are 132immediately disordered by the influence of these poisons on the tongue, stomach, and lower bowels of animals, so instantaneously, that it is impossible absorption should have already taken place.

Although the general proposition seems to be established, that the brain is not immediately necessary to the action of the heart, yet it must not lead us to the conclusion that the heart is therefore incapable of being affected by violent impressions on the nervous system; the fact is quite otherwise, for although the brain may be removed, and the circulation be nevertheless maintained by artificial respiration, yet an injury of another kind inflicted on the brain, may be followed by those immediately fatal consequences which decapitation itself would not produce; thus is a blow on the head commonly followed by syncope, and there are certain poisons that would seem to act in the same manner, such is the Infusion of Tobacco,^[224] which suspends the action of the heart long before the animal ceases to respire, and kills by producing syncope, although in this latter case it has been questioned whether the spinal marrow may not be primarily affected, which has been shewn by recent experiments to have an intimate relation with the action of the heart. Be this as it may, it is sufficiently obvious, that the second division of the first class is sanctioned by theory, and confirmed by experiment.

We come now to speak of the Second Class,—of those Poisons which enter the circulation, and act through that medium on the heart, brain, and alimentary canal. These organs, however, are affected in very different degrees by different poisons, or even by the same poisons, under different circumstances. Mr. Brodie has shewn that vegetable poison, although when introduced into the alimentary canal affect life, in consequence of the nervous sympathy which subsists between these surfaces and the common sensorium, yet, that the same poisons applied externally to a wound, produce their effects exclusively through the medium of the circulation, being conveyed to the brain only by mixing with the blood in its vessels, and not by being conveyed through the lymphatics, for a ligature upon the great blood-vessels prevents their producing deleterious effects; whereas a ligature upon the thoracic duct, or general canal through which all the absorbents pour their contents into the blood, does not in the least retard or prevent the operation of the poison. There are also several of the mineral poisons which, whether introduced into the stomach, or applied externally to a wound, poison the animal in consequence of being carried into the circulation. It had long been supposed that Arsenic occasioned death by inflaming the stomach; but Mr. Brodie has very satisfactorily shewn that its influence arises from its absorption, and that it must be regarded rather as a vital, than as a chemical agent. In the first place, he has found the inflammation of the stomach, in several cases, so 133slight, that on a superficial examination it might have been easily overlooked; and, in most of his experiments with Arsenic, death took place in too short a time to be considered as the result of inflammation; and in the next place, in whatever manner the poison is applied, whether externally to a wound, or internally to the membrane of the stomach, the inflammation is confined to the stomach and intestines; and, indeed, it is commonly more violent, and even more immediate, when applied to a wound, than when internally administered; and it also precedes any inflammation of the wound. This important fact was proved by an experiment made by Mr. Hunter and Sir Everard Home, and subsequently by the repeated investigations of Mr. Brodie.

It has been just stated that after a poison has found its way into the circulation, it expends its virulence upon some particular organs. In some cases this is much more striking than in others. The preparations of Baryta, and of Tartarized Antimony, attack the heart, and occasion death by syncope. Arsenic is less definite in its action, it influences both the brain and the heart, but with different degrees of force in different cases, so that it is often difficult to ascertain which of these organs is the first to fail in its functions. Hydro-cyanic Acid is absorbed, and destroys life by its action upon the nervous system, whose energies it would seem to extinguish without any ostensible injury to the respiration and circulation; for in all those animals which were killed by it in the experiments of Orfila, Brodie, and others, the heart was found acting regularly, and circulating dark-coloured blood; and in some cases, this phenomenon was visible for many minutes after the animal was in other respects apparently dead.

Some substances would seem to direct their powers to various parts of the alimentary canal; and the appearance so produced might be mistaken for the effects of the local action of the poison, had they not been clearly proved by experiment to have arisen from an application addressed through the medium of the circulation; thus is inflammation of the primæ viæ induced by the contact of Arsenic with an external surface of the body!

The Third Class of my arrangement includes those poisons which enter the circulation, and, through that medium, expend their influence upon the spinal marrow, without directly involving the functions of the brain. M. Majendie, in the year 1809, submitted to the first class of the French Institute a series of experiments which had conducted him to the extraordinary result above stated. He found that an entire class of vegetables (the bitter Strychnus) possesses this singular property.

The Fourth Class comprehends all those substances which destroy life by a local action upon the alimentary canal, not by any impression upon their nerves, but by simply inducing a fatal lesion in the membranes.

Through one or more of the above modes of operation all poisons may be said to produce their fatal effects. In some cases a poisonous substance will be found to act in several different ways; thus, the Nightshade is evidently absorbed, carried into the circulation, and is enabled, through that medium to act upon the brain; at the same time it exerts a local action upon the stomach, although less violent than that occasioned by the acrid poisons; it moreover would appear, upon some occasions, to act directly through the medium of the nerves, like those substances 134which have been received in our first class, or else, how shall we explain the fact of the pupil of the eye becoming permanently dilated by the contact of the Belladonna with the tunica conjunctiva? It would appear therefore that this plant unites within itself all the three great modes of action, upon which I have just attempted to establish a physiological arrangement of Poisons. So again, Corrosive Sublimate, although placed in the fourth division, as being a substance which destroys by inflicting local mischief, is nevertheless capable of being absorbed. The embarrassments, however, which might be supposed to arise from this double mode of operation, are of but trifling importance. It is to the primary operation of a poison to which we are to direct our attention, the subsequent effects are less important in as much as they are more capable of being controlled.

Having thus offered a summary of our present views respecting the physiological action of Poisons, we are prepared to lay down a general plan of treatment, which, it will be seen, can only be successful when conducted on principles strictly conformable with the just notions which the preceding experiments have so satisfactorily established.

Where a poisonous substance has, either through accident or design, found its way into the alimentary canal, three important indications are, if possible, to be fulfilled; and under these heads I shall offer such observations as may serve to instruct the practitioner in the philosophy of the general treatment, reserving the details to be observed in that of each poison, for more particular notice in a subsequent part of the work, where the history of these substances will be individually considered. The indications to which I allude are the following, viz.

1. The immediate ejectment of the poison from the body, by the operation of vomiting and purging.

Whatever may be the nature of the poison, we should endeavour with all possible expedition, to eject it from the body; and upon the promptness with which this is effected, the safety of the patient will generally depend; for the dangerous effects of such substances advance in a very increasing ratio, with the time they remain in contact with a living surface. A question may arise, whether in some cases it would not be judicious to attempt in the first instance the neutralization or decomposition of the poison; where a mineral acid, or a caustic alkali has been swallowed, it would undoubtedly be right to neutralize, and dilute it, as soon as possible, and then to excite vomiting, which may be advantageously effected by thrusting the finger down the throat, or by tickling the internal fauces with a feather: where an emetic is at hand, whatever may be its nature, it should be promptly given, but if circumstances will allow us the opportunity of selection, Antimony, Ipecacuanha, &c. should be rejected, and Sulphate of Zinc, or Sulphate of Copper, for several reasons, be preferred; in the first place they do not require much dilution^[225] for their action, a circumstance of no small importance in the treatment of poisons that act by being absorbed; in the next place, they are extremely expeditious, a dose of fifteen or twenty grains producing almost instantaneous vomiting, without 135exciting that previous stage of nausea which so frequently characterises other emetics, and which occasions a state of the vascular system highly favourable to the function of absorption, (as I have so fully explained at page 86, &c.)

The practice of emptying the stomach by means of a syringe, as proposed by Boerhaave, has lately been revived with all the confidence of a new invention. There are cases of narcotic poisoning in which there can be no doubt it would furnish the practitioner with a valuable resource, but I much fear that it will be found to be less successful than its more sanguine advocates have anticipated; for where the stomach has so far lost its power as to be insensible to the stimulus of a potent emetic, the chances of recovery are small; the practice, however, in such cases ought never to be neglected, for it cannot possibly do harm, and may perhaps be beneficial.

After all has been ejected, which the operations of art can effect, we are to proceed, without delay, to the fulfilment of the second indication; viz.

2. The Decomposition of any remaining Portion, and the adoption of measures best calculated to obviate its absorption.

Where the substance is in a solid form, and acts by absorption, we should be very cautious how we favour its solution; while, if it exists in a liquid state, our object must be to render its active portion insoluble; this problem involves a series of questions which are wholly chemical. In order to prevent, or retard, the absorption of the active matter, we must, to a great degree, depend upon the agency of vital adjuvants; this latter indication however does not apply to Corrosive Sublimate and other substances which act upon the stomach locally, and are not absorbed; copious dilution also, in such cases, will frequently disarm the poison of its virulence,^[226] but it should be followed as quickly as possible by vomiting. In cases where the poison requires to be absorbed, before it can display its energies, it would be generally unsafe to administer any solvent. Nothing therefore can be less true as an aphorism, nor more dangerous as a precept, than the unqualified assertion of Boerhaave, “Aqua omnia venena enervat, quæ cum aqua misceri possunt.” (Prælect. in Instit: T. vi. p. 289.) Alkaline solutions and Magnesia, in cases of the ingestion of arsenic, accelerate its fatal effects, by promoting its solution,^[227] whereas Lime, or its Carbonate, has as an opposite tendency,^[228] in consequence of the insolubility 136of Arsenite of Lime; so again, Orfila has shewn that the pernicious qualities of the Muriate of Baryta are counteracted by the administration of any soluble Sulphate, which renders the former substance insoluble. In cases where Verdegris has been swallowed, the administration of vinegar greatly increases its virulence, as M. Drouard has ascertained, by converting the substance into a soluble acetate of copper. This view of the subject will explain why the pure earth Baryta is so slow, and comparatively inert, in its effects upon the system, while its muriate is distinguished by the extreme rapidity and virulence with which it operates. The propriety of administering vinegar, lemonade, and different acid potations, in order to counteract the baneful effects of Opium, which has been so often questioned, will thus also receive ample explanation; it must appear that, if any quantity of the substance of opium remain in the primæ viæ, acid, or mucilaginous drinks will, by favouring its solution and absorption, accelerate its fatal effects;^[229] but should it have been previously ejected from the stomach, that then the anti-narcotic influence of a vegetable acid^[230] may remove the consecutive stupor and delirium, and thus realize the expectations which Virgil has so poetically raised.

Chardin, in his travels through Persia, informs us that when a Persian finds himself in a distressed situation, he has recourse to a piece of opium as large as the thumb, and that immediately afterwards he drinks a glassful of vinegar; by which he is thrown into a fit of laughter, terminating in convulsions and death.

With regard to the use of Antidotes, it has been already stated how little they are to be depended upon; in certain cases, however, we are bound to acknowledge their power, but they should be very rarely trusted, unless subsequent to, or in conjunction with, the operation of an emetic; in many cases the effects of this latter remedy may be promoted by the ingestion of liquids holding the particular antidote in solution, a practice which offers the double advantage of accelerating the elimination of the poison, and at the same time of decomposing any which may remain. Orfila has fully established the fact of Albumen being a counter-poison to Corrosive Sublimate; 137vomiting may therefore be very judiciously promoted in cases of such poisoning by water holding the white of egg in solution; with equal effect, where Verdegris has been swallowed, sugared water may be used as a diluent to encourage emesis; and Muriate of Soda in solution will be found the most efficient antidote to Nitrate of Silver; and Sulphate of Magnesia to Acetate of Lead. Where an emetic salt, like Tartarized Antimony, has been taken, copious dilution with common water will in general so provoke vomiting, as to render it its own antidote; but it may be useful to remember, that the Infusion of Galls, and according to Berthollet, the Decoctions of Bark, at the temperature of from 30° to 40° Fah. have the power of decomposing it; while Orfila considers milk the most efficient counter-poison to the Sulphate of Zinc.

Having ejected from the stomach all the poisonous matter we can by vomiting, and attempted to decompose what remains, we are to pursue such measures as may be calculated to prevent the absorption of the poison into the circulation; it has been already observed that on this account nauseating emetics should be avoided; the reader is now requested to refer to our exposé of the celebrated doctrine of Majendie, (page 86, note) and he will see that Venesection proves one of the most powerful means of exciting the function of absorption; hence in poisoning by arsenic, such an expedient should never be recommended,^[231] while a particle of that substance remains in the body; where Corrosive Sublimate has been swallowed, the same precaution is unnecessary. The last indication which remains to be fulfilled is—

3. To anticipate the occurrence of the Consecutive Phœnomena, and to combat them by appropriate treatment.

This is to be conducted on the general principles of Therapeutics; the treatment must necessarily vary in each particular case. Where the exhaustion of nervous energy is to be feared, as after poisoning by Prussic Acid, ammonia, and other diffusible stimulants, together with external warmth, will furnish the best resource; for the same reason Venesection should be performed with great caution and judgment after a narcotic poison. Where, on the other hand, inflammatory action is to be anticipated, it is unnecessary to detail the plan of treatment which may be adopted with the greatest chance of success. In cases where the nervous system is stupified, the symptoms may be combated by vegetable acids, infusion of coffee, &c. but where it is in a state of præternatural excitement, recourse must be had to opiates.

ESCHAROTICS:^[232]

Substances whose application to the animal solids, erodes, or decomposes them.

138The operation of these bodies may, in general, be considered chemical; for having destroyed the life of the part to which they are applied, they cause, as if by a species of resulting affinity, the elements of the animal matter to enter into a new state of combination; this is well exemplified in the action of caustic potass, where the nascent elements thus disengaged by the decomposition of the animal substance, reunite in proportions to generate an oily matter, which may be observed to form a film over the ulcerated surface, while the excess of nitrogen and hydrogen constitute ammonia, which is disengaged during the action of the caustic; and may be rendered sensible by inverting over the surface, a small jar moistened with muriatic acid, when the fumes of Muriate of Ammonia become visible.^[233]

Their surgical value consists in their power to remove excrescencies, to establish an ulcer, or to convert an ulcerated surface into a simple sore.

IV. OF MECHANICAL REMEDIES.

This subdivision includes those classes of remedies, whose operation depends entirely upon mechanical principles; and we must agree with Dr. Murray in considering them as the least important of all the articles which we have enumerated, and which cannot therefore constitute objects of elaborate inquiry.

ANTHELMINTICS:

Remedies which expel worms^[234] from the intestinal canal.

It has been already stated, (page 90) that certain bodies have the power of increasing the peristaltic motions of the intestinal canal, by operating as mechanical stimulants upon its fibres; in this manner the filings of tin and iron, or the irritating down which covers the pods of the Dolichos Pruriens, are supposed to act in dislodging and evacuating the worms from the intestines. But there is a variety of remedies employed as vermifuges, which must owe their effects to a very different mode of operation; Bitters for instance appear to prove an absolute poison^[235] to these animals, while they, at the same time, give an increased tone to the organs of digestion; from whose debility the generation of worms would seem to arise. Other remedies, again, obviously depend upon their simple cathartic property, for the powers which they possess in the evacuation of worms. See Terebinthinæ Oleum—Cambogia.

139In the cure of Ascarides the local application of the remedy becomes necessary, in the form of glyster, and which acts both mechanically in washing out the gut, and medicinally in proving obnoxious to the animals. According to the experience of some of our best practitioners, a strong decoction of the Semina Santonici proves most efficacious upon these occasions.

DEMULCENTS:

Medicines which are capable of shielding sensible surfaces from the action of acrid matter, by involving it in a mild and viscid medium.

It cannot be denied that where these remedies admit of direct application, considerable benefit may arise; in the progress of a catarrh, we have all experienced the relief that may be occasioned by lubricating the fauces with demulcents, which, by soothing the top of the trachea, quiets, by a kind of contiguous sympathy, the whole pulmonary structure; in certain states of intestinal irritation, the same remedies have furnished considerable benefit, and in ophthalmia, relief has been obtained by the application of a demulcent to the inflamed conjunctiva, by which it is defended from the irritation of the tears; see also Formula 61; but in parts beyond the reach of the first passages, and to which no fluid can arrive but through the medium of the secretions, it is very difficult to explain the principle upon which their beneficial operation can depend; and it seems indeed highly probable that they act in such cases as simple diluents, for the process of digestion must necessarily deprive them of their characteristic viscidity. The administration of demulcent drinks in gonorrhæa is probably of no farther service in assuaging the ardor urinæ, than an equivalent quantity of pure water; although Dr. Murray observes, “it is sufficiently certain, that many substances, which undergo the process of digestion, are afterwards separated in their entire state from the blood, by particular secreting organs; and there is, continues he, no gland which has this power more particularly than the kidneys; substances received into the stomach and digested, afterwards passing off in the urine with all their peculiar properties.” This is undoubtedly very true, but mucilaginous substances rarely or never pass off in this manner; if they evade the assimilative functions, they pass through the alimentary canal, and are thus eliminated. I can state, as the result of experiment, that the urine undergoes no change except in the relative proportion of its water, by the copious and repeated administration of mild mucilages. Dr. Saunders has very justly remarked that the long list of Ptisans, Decoctions, &c. usually prescribed upon these occasions, generally owe their virtues to the watery diluent itself.

The pharmaceutical applications of this class of medicines constitute, perhaps, not the least part of their value, by which we are enabled to introduce acrid substances into the stomach with safety and effect; but such services will more properly fall under our notice in a future part of the work.

DILUENTS:

Watery liquors, which increase the fluidity of the blood, and render several of the secreted and excreted fluids less viscid.

There are certainly few remedies whose operation is more simple, obvious, 140or important; and yet there are scarcely any whose value has been more mistaken, or whose application has been so frequently perverted through the suggestions of false theory; water is the universal beverage of animals, and the necessity of its supply is indicated by thirst, a sensation which in excess, is borne with less tranquillity even than that of hunger; in certain morbid states of the body its presence is to be regarded as indicating the necessity of copious potation; and yet how often has the prejudiced physician, under such circumstances, aggravated the pressure of disease, by adding the sufferings of Tantalus. In febrile affections, the irritation of thirst tends to keep up the disease, and hence diluents, besides the other beneficial effects which they may produce, must be regarded as important remedies. There are also diseases of the alimentary canal which may be removed by the same agents; when water is conveyed into the intestines it will have a tendency, by mixing with, and diluting the biliary secretion, to diminish its acrimony, and thus to obviate a source of morbid irritation; the dilution of the chyme and chyle may also have a salutary tendency, and favour the absorption of the finer and more nutritive parts of the lacteals; and by increasing the fluidity of the mass, expedite the numerous combinations which it is destined to undergo. The blood itself is also thus modified in its fluidity; although it has been very truly observed that in healthy bodies, or such as are without any obstruction of the excretions, an unusual distension of the vessels cannot be produced, or at least long subsist; for it is evident that such an increased quantity of water in the blood will immediately pass off by one or other of the excretions; this effect, however, in itself, renders the operation of diluents of signal service in the treatment of the disease; in consequence, for instance, of their disposition to pass off by urine, they furnish valuable resources in diseases of the urinary organs, allaying the pain of strangury, and the irritation from an inflamed bladder. From these observations, the practitioner will be led to appreciate the value of diluents; and many of the beneficial effects which are daily experienced from the copious potation of mineral waters, are, without doubt, to be wholly attributed to simple dilution. See Aqua.

It is here necessary to say a few words upon the misapplication of this order of remedies. Dr. Davy found by experiment that when an animal is bled to death, the last portions of blood that flow are of a much lower specific gravity than that which flows first, in consequence of the former containing more water, which it may be inferred was derived by the increased activity of the absorbents, exerted chiefly on mucous and serous membranes. Since then venesection promotes and accelerates absorption,^[236] it is clear that, in inflammatory diseases, where we have recourse to blood-letting, in order to diminish the volume of circulating fluids, we ought not to suffer the patient to indulge in an unrestrained use of liquids, which he eagerly demands to satisfy a thirst which, in all probability, is the natural consequence of increased absorption. In such cases, it is often better to take liquids in small divided doses, which will have the effect of moderating the thirst, without overloading the arterial system, and bringing on that tension and plenitude which are liable to be produced by swallowing too large a proportion of liquids.

In the use of water upon such occasions, it may moreover be observed, that its temperature ought to be attended to; as a general rule it may be 141laid down, that in the cold stage it should be hot, in the hot, cold, and in the sweating, tepid.

With regard to the value of diluents, as capable of promoting the operation of other remedies, many observations of great practical importance might be adduced; but this subject will be more properly elucidated when we come to consider the influence of solubility in modifying the activity of medicinal substances, and which constitutes a very curious and interesting object of chemico-medical enquiry.

While speaking of Diluents it may be cursorily noticed, that water appears, under certain circumstances of the body, to suffer decomposition, and to have its elements appropriated to new combinations. Count Rumford has endeavoured to prove, that the surprisingly small quantity of solid food which is sufficient for nourishment, when converted into rich and palatable soup, is owing to the culinary process having prepared the water for chemical decomposition,^[237] and that this is ultimately effected during the act of Digestion.^[238] It cannot be denied that the exorbitant potation of water has a tendency to produce fat, but this may depend upon the vascular distention which is thus occasioned. Gin drinkers, before they become materially injured by the habit, grow extremely corpulent, as may often be witnessed in unfortunate cyprians of the lower orders. Can the hydrogen of the spirit contribute to this effect?

EMOLLIENTS:

Substances whose application diminishes the force of cohesion in the particles of the solid matter of the human body, and thereby renders them more lax and flexible.

According to this definition, which we derive from Dr. Cullen, the primary operation of emollients would appear to be purely mechanical, for they are insinuated into the matter of the solid fibre, and either diminish its density, or lessen the friction between its particles; this explanation will undoubtedly apply to those emollients which consist of unctuous bodies, and which are introduced into the animal fibre by friction; but it is evident that the beneficial effects of Cataplasms and Fomentations cannot be so explained; for in these instances, none of the materials can be absorbed through the entire cuticle; and yet the relaxation and consequent ease which such warm applications produce on inflamed surfaces is very considerable, but it must be wholly attributed to the relaxing effects of warmth and moisture upon the extreme vessels of the surface, propagated by contiguous sympathy to the deeper seated organs.

The operation of those substances which afford relief to excoriated surfaces by their bland qualities, as mucilaginous lotions in erysipelatous affections, is too obvious to require explanation.

Having thus investigated the manner in which medicinal substances produce their effects upon the living system, we shall be better prepared to appreciate the advantages which are to be derived from their combination with each other, and to escape the too common error of uniting in one formula, remedies which are rendered adverse by the incompatibility of their physiological actions.

OF MEDICINAL COMBINATION.

“Variorum mixtura novas sæpe vires generet, in simplicibus nequaquam reperiundas longe saluberrimas.”

It is a truth universally admitted, that the arm of physic has derived much additional power and increased energy, from the resources which are furnished by the mixture and combination of medicinal bodies. I by no means intend to insinuate that the physician cannot frequently fulfil his most important indications by the administration of one simple remedy; I only contend that, in many cases, by its scientific combination with other medicines, it will not only act with greater certainty and less inconvenience, but that its sphere of influence may be thus more widely extended, and its powers so modified or changed, as to give rise to a remedy of new powers. Such a theory is amply justified by the state of combination in which certain medicinal principles are found in our more efficient vegetable remedies, while the medicinal practice founded upon it is thus, as it were, sanctioned by Nature’s own prescriptions; enter but her laboratory, and you will soon be satisfied, that many of her potent remedies do not owe their valuable powers to any one specific ingredient, but to the combined or modified energies of various, and sometimes opposite principles. This view of the subject opens an interesting and unexplored field^[239] of medical and chemical research, and I shall endeavour to avail myself of the novelties its investigation may present, and of the hints it may suggest for the improvement of extemporaneous combination. By contemplating the laws by which Nature effects her wise purposes, we may learn to emulate her processes, and even in some cases to correct and assist her operations:^[240] such at least has been the happy result of our labours in the other 146departments of natural knowledge. It is said for instance that by observing the means used by nature for preventing the diffusion of light in the eye-ball, Euler derived an important hint for the improvement of his telescope; and more lately, the structure of the crystalline humour of the eye has been successfully imitated in the invention of achromatic lenses. On the other hand, it is hardly necessary to observe to what extent these instruments of art are capable of improving and multiplying the powers of that natural organ, to the contemplation of whose structure and functions, we are, as I have just stated, so greatly indebted for their origin and perfection. So shall I endeavour to shew, in the progress of this work, that the combinations of nature, as exemplified in her more valuable remedies, are capable, if properly studied, of suggesting many important hints for improving the arrangements of art; while art in return may frequently supply the defects, or extend the advantages of natural compounds.

AN ANALYSIS
OF
THE OBJECTS TO BE OBTAINED BY MIXING AND COMBINING MEDICINAL SUBSTANCES.

The objects to be attained, and the resources which are furnished, by Medicinal Combination, together with the different modes of its operation, and the laws by which it is governed, may with much practical advantage be arranged in the following order.

I.
TO PROMOTE THE ACTION OF THE BASIS, OR PRINCIPAL MEDICINE.

A.—By combining together several different Forms, or Preparations, of the same substance.

The utility of such a combination is obvious, whenever we desire the full and general effects of all the principles of a medicinal body in solution; thus, where the Bark is required in the cure of an intermittent fever, and the stomach will not allow the exhibition of the powder, it will be eligible to conjoin in one formula, the tincture, decoction, and extract, as exemplified by Formulæ 42, 126, 127. The necessity of such a combination may be expressed by the following canon. Whenever the chemical nature of the medicinal substance will not admit of the full solution of all 147its active principles in any One Solvent, and its exhibition in substance is at the same time impracticable. For farther illustrations see Form. 2, 25, 33, 38, 70, 109.

Practitoners, probably without having reasoned upon the theory, have very generally adopted the practice, of combining the different solutions of the same substance; for in the prescriptions of practical physicians we commonly find, that the decoction or infusion of a vegetable remedy is quickened by a certain portion of a corresponding tincture.

B.—By combining the Basis with Substances which are of the SAME NATURE, that is, which are INDIVIDUALLY capable of producing the same effect, but with less energy than when in combination with each other.

Dr. Fordyce first established the existence of the singular and important law, that a combination of similar^[241] remedies will produce a more certain, speedy, and considerable effect than an equivalent dose of any single one; a fact which does not appear to have been known to any ancient physician. The earliest mention of it that I can find is by Valisnieri, the favourite pupil of Malpighi, who filled the medical chair at Padua in 1711, nearly ninety years before Fordyce published his valuable memoir on the combination of medicines, but he does not attempt any generalization^[242] of the subject; he merely states, as the result of careful experiments, that twelve drachms of Cassia Pulp are about equivalent in purgative strength to four ounces of Manna; and yet, says he, if we give eight drachms of Cassia Pulp, in combination with four drachms of Manna, we obtain double the effect! How, adds the professor, can this possibly happen? Surely the very contrary ought to obtain, since four drachms of Cassia are much more than equivalent to an equal weight of Manna; the strength of the former being to that of the latter as 8 to 3.

The truth of this law of medicinal combination must be continually felt by the practitioner in the ordinary routine of his practice, viz.

Narcotics will better fulfil the intention of allaying irritation and pain, when composed of several of such medicines in combination, than when they consist of any single one, even should the dose, in this latter case, be increased. See Formulæ 3, 4, 5.

Antispasmodics acquire increased efficacy by the application of the same principle. Form. 20, 21, 22, 23, 24, 25.

Bitter Tonics are also thus exalted, see Form. 39, 40, 41. The 148beneficial effects, however, which arise from combinations of this kind will admit of a satisfactory explanation upon another principle; we may, for instance, consider them as medicines, differing from each other in their composition, and producing by their union an assemblage of bitter, astringent, and aromatic principles.

Aromatic and Diffusible Stimulants. There are perhaps no remedies which receive greater mutual benefit be intermixture with each other, than the individuals which compose this class; for they not only thus acquire increased force and efficacy, but at the same time they lose much of their acrimony; if, for instance, any one spice, as the dried capsule of the Capsicum, be taken into the stomach, it will excite a sense of heat and pain; in like manner will a quantity of Black Pepper; but if an equivalent quantity of these two stimulants be given in combination with each other, no such sense of pain is produced, but, on the contrary, a pleasant warmth is experienced, and a genial glow felt over the whole body; and if a greater number of spices be joined together, the chance of pain and inflammation being produced is still farther diminished. The truth of this law is also strikingly illustrated, as Dr. Fordyce has observed, by that universal maxim in cookery, never to employ one spice, if more can be procured; the object, in this case, being to make the stomach bear a large quantity of food without nausea.^[243] This same principle also finds an illustration of its importance, as it regards the class of stimulants, in the following preparations of our Pharmacopœia, viz. “Pulvis Cinnamomi Compositus; Infusum Armoraciæ compositum; Infusum Aurantii Compositum; Spiritus Lavendulæ compositus; Tinctura Cinchonæ composita; Tinctura Valeriana Ammoniata; and the Confectio Opii, the elegant and scientific substitute for the celebrated Mithridate or Theriaca. The practitioner is also referred to Form. 45, 47, and to Allii Radix.”

The local action of these stimulants would appear to be placed under the dominion of the same law, and perhaps the origin of the custom, so long observed, of mixing together the varieties of snuff, may thus receive a plausible and philosophical explanation; certain it is that by such combination the harsh pungency of each ingredient will be diminished, whilst the general potency of the application, in exciting the nerves, will be increased, and rendered more grateful; the same principle will direct the formation of safe and efficient plaisters and lotions; the Emplastrum Cumini of the London, and the Emplastrum Aromaticum of the Dublin Pharmacopœia, offer examples of its judicious application.

Astringents. For illustrations see Form. 51, 58.

Emetics are certainly more efficient when composed of Ipecacuan united with Tartarized Antimony, or Sulphate of Zinc, than when they simply consist of any one of such substances in an equivalent dose. See Form. 63, 65.

Cathartics not only acquire a very great increase of power by combination with each other, but they are at the same time rendered less irritating 149in their operation; the Extractum Colocynthidis compositum affords an excellent example of a compound purgative mass being much more active and manageable, and less liable to irritate, than any one of its components separately taken. Additional examples of this fact are furnished by Formulæ 70, 76, 78, 79, 81, 88. In many cases, however, the fact of purgatives thus accelerating and correcting each other’s operation may be explained by considering them as substances endowed with different powers, as already demonstrated, (p. 88), and which will be more fully considered in the third division of this Essay.

Diuretics. Under this class of medicinal agents it may be observed that, whenever a medicine is liable to produce effects different from those we desire, its combination with similar remedies is particularly eligible, by which the action of the basis may be directed and fixed; thus the individuals which compose the class of Diuretics are uncertain in their operation, and disposed when exhibited singly to produce diaphoretic, and other contrary effects; it is, therefore, in such cases, highly judicious to unite several of them in one Formula, by which we increase their powers, and are more likely to ensure their operation. Formulæ 101, 103, 108, 109, 110, 111, 115, are constructed upon this principle.

Diaphoretics. Our maxim, “Vis Unita Fortior,” certainly applies with equal truth to this class of medicinal agents. Form. 122, 124.

Expectorants. More is frequently to be gained by the co-operation of these remedies than can be obtained by the exhibition of them separately, as in Form. 134, 135.

Demulcents do not appear to obtain any other benefit from combination than, occasionally, a convenience and efficacy of application arising from a suitable degree of consistence and solubility. See article “Trochisci.”

The operation of the law which has thus formed the first object of this inquiry, will be found, like every other, to have a natural and well defined limit; it is easy to perceive that by multiplying the number of ingredients too far, we shall either so increase the quantity and bulk of the medicine as to render it nauseous and cumbersome, or so reduce the dose of each constituent as to fritter away the force and energy of the combination.

The propriety of combining several stimulants, of the diffusible class, in one formula, has been questioned on different grounds. Dr. Chapman, in his work on Therapeutics, adduces some arguments on this point, which, although they fail in establishing his general position, certainly suggest an important exception to the practice in question; “by directing,” says he, “stimulating remedies, separately, we shall economise our resources in many lingering diseases.” The justness of this statement must be admitted to its fullest extent, and practitioners will, on certain occasions, do well to act in conformity with the views that suggested it; for instance, in the feeble forms of protracted fevers, where the indications are to be met with the continued action of stimulants, it will certainly be salutary to alternate the use of camphor, ammonia, and other remedies of a similar nature, in preference to presenting them all at once in combination, so that the system may not lose its susceptibility by the continued impression of the same stimulant; the same motive should induce us, on particular occasions, to employ in succession different narcotics, for each of them affects sensibility in its own peculiar manner.^[244] The nervous system, as Richerand has 150very justly observed, may be compared to a soil, rich in different juices, and which requires the cultivator to plant the germs of a diversified vegetation to develope the whole of its fecundity; to insure a perpetual return, therefore, it will be right to sow a succession of different seeds. Hoffman also has offered us some advice upon this subject; he directs us in the treatment of chronic diseases to suspend the administration of remedies, at intervals, and afterwards to resume them, lest the system should become habituated, and ultimately insensible to their influence.

But there remains for our investigation a still more important precaution respecting this law of medicinal combination;—that, in combining substances in the manner, and for the object just related, the practitioner should be well satisfied that their medicinal virtues are in reality practically Similar, or he will fall into an error of the most fatal tendency; it has been already shewn, and I hope I shall not be considered tedious by again directing the reader’s attention to the fact, that medicines are not necessarily similar because they have been arranged in the same artificial division of remedies; in order to establish a perfect similarity their operations must be found by experience to continue similar under every condition of the human body; and that, moreover, they must owe such similarity to modes of operation which are compatible with each other, and consonant with the general mode of cure; we have only to refer to the history of Diuretics (page 92) for a full illustration of this important truth; thus Squill, Calomel, and Digitalis, are each powerful Diuretics, but nevertheless they cannot be considered similar remedies, since Digitalis will entirely fail in its effects in the very cases that Calomel and Squill succeed; and Squill will prove inert when Digitalis is capable of producing the most powerful influence; this arises from their modes of operation being dissimilar, and consequently requiring for their success such different states of the living system. Squill, it will be seen, acts primarily on the urinary organs, by stimulating the secreting vessels of the kidneys; Mercury, on the contrary, acts primarily on the absorbents, and secondarily on the kidneys; whereas Digitalis produces its effects by diminishing arterial action, and increasing that of absorption.

Dr. Blackall, in his “Observations upon the Cure of Dropsies,” has offered some remarks so valuable in themselves, and so illustrative of this important subject, that I shall take leave to quote the passage. “Many physicians,” he observes, “are fond of combining Squill, Calomel, and Digitalis, as a diuretic in dropsy; a practice unsafe, and not very decidedly possessing the merit even of being consistent. Digitalis greatly depresses the action of the heart and arteries, and controls the circulation, and it seems most unreasonable to believe that its curative powers can be independent of such an effect; on the other hand, Mercury, if it does not pass off quickly, is always exciting fever, and raising and hardening the pulse; speaking from experience, where the urine is coaguable, and Digitalis agrees, both the others are, often at least, positively injurious. On the contrary, where the urine is foul, and not coaguable, and Squills with Calomel render service, I have on that very account, made less trial of Digitalis, and cannot therefore speak of it from much experience.” See Form. 103, and the note thereon.

151The individual medicines which compose the class of Diaphoretics vary no less in their primary operations, as the synoptical arrangement at page 99 very fully exemplifies; thus, in the cure of intermittent fevers, diaphoretics are useful both in the paroxysm, and during the intermission; in the first case they shorten its duration; in the second they support the tone of the extreme vessels, and prevent its recurrence; but in these opposite states of disease a very different kind of diaphoretic is required—to fulfil the first indication, a cooling and relaxing one is necessary; to answer the second, the stimulating diaphoretic is exacted; the one may be said to solicit, the other to extort, perspiration. So again Emmenagogues can only be considered relative agents, since the suppression of the catamenia may depend upon, or be connected with, very different states of the system; in some cases with a diminished, and in others with an increased state of excitement; for on many occasions the suppression of the menses is the effect, and not the cause of disease; Boerhaave has very justly observed, that it is a most dangerous error to ascribe all the diseases of young females to a retention of the catamenia, which often do not appear because the patients are disordered from other causes. If, therefore, we were to attempt a combination of the several medicines which have gained reputation as Emmenagogues, it is very obvious, that we should bring together an assemblage of adverse and incompatible remedies; nor would the physician be less inconsistent were he to combine Expectorants, without a due regard to their modes of operation; it is only necessary to observe their classification, as presented at page 102, to become satisfied how greatly the success of such remedies must depend upon their scientific adaptation to each particular case.

The class of Antispasmodics may likewise embrace remedies of the most opposite tendency, for spasm may occur under the most opposite circumstances—in an extreme condition of weakness, as in nervous affections, and in an highly excited state, as in cholic, &c.; it is hardly necessary, therefore, to point out the mischief that must arise from the fortuitous and indiscriminate admixture of the individual substances which are thus unavoidably arranged in the same artificial classification. Bark and Steel are also too often considered as equivalent Tonics; in Dropsy, says Dr. Blackall, it is far otherwise, the former being infinitely to be preferred after the dropsy of young persons, of acute disease, and of sound stamina; the latter being suited to a vitiated rather than to a feeble habit, and indicated more by a pale sallow complexion, and a want of red colour in the blood, as shewn by the paleness of the lips, than by any other signs. Need we then adduce farther illustrations of the obvious but important fact, that the terms employed to denote the different classes of remedies are frequently but relative ones, expressive of effects which are produced only in reference to a particular state of the living body? and as this necessarily varies in different states of health and disease, it follows that medicines are convertible agents, and that when we attempt to institute general rules respecting their administration, without taking into consideration the constitution and circumstances of the patient upon whom they are to operate, we shall generally be disappointed in the result. We may say of medicines what Van Swieten said of diet, “to assert that such, or such a thing be wholesome, without a knowledge of the condition of the person for whom it is intended, is like a sailor pronouncing the wind to be fair without knowing to what port the vessel is bound.” Boerhaave was 152so fully impressed with this truth that he exclaimed, “nullum ego cognosco remedium, nisi quod tempestivo usu fiat tale.”

Although medicines which produce the same ultimate effects by modes of operation obviously different, cannot be considered SIMILAR, in the sense affixed to the term in the present section, yet if these different modes of operation be not physiologically incompatible with each other, the union of such remedies may not only be admissible, but even useful; and it will, accordingly, constitute an object of inquiry in a succeeding section. (III. A.)

C.—By combining the Basis with Substances of a DIFFERENT NATURE, and which do not exert any Chemical influence upon it, but are found, by experience, to be capable of rendering the Stomach, or System, or any particular organ, more susceptible of its action.

Thus it is that the system is rendered more susceptible of the influence of Mercury, by combining it with Antimony and Opium.^[245] Where the stomach is insensible to impressions, the exhibition of Opium previous to, or in combination with, any active medicine, often assists its operation; this is remarkably striking in some states of mania, when emetics will fail, unless the stomach be previously influenced and prepared by a narcotic; indeed, in ordinary cases of inirritability of stomach, the addition of a small quantity of opium will often render an emetic active.^[246]

So again the system, when it is in that particular condition which is indicated by a hot and dry skin, is unsusceptible of the expectorant powers of Squill, unless it be in union with antimony or some powerful diaphoretic, (Form. 134.) Squill is by no means disposed to act upon the urinary organs, when exhibited singly; but calomel, and some other mercurial preparations,^[247] when in conjunction with it, appear to direct its influence 153to the kidneys, and to render these organs more susceptible of its operation; (103, 106.) Upon the same principle, Antimonial Wine quickens the operation of saline cathartics (69); Opium increases the sudorific powers of Antimony (124); and the purgative operation of Jalap is promoted by Ipecacuan (84). Dr. Aikin asserts that fifteen grains of the former purgative when combined with two or three grains of the latter root, will purge more than double that quantity of Jalap when administered without such an adjunct.

Sir John Pringle speaks of the advantages which may be obtained by combining an alkali with a bitter infusion, by which the diuretic effects of the former will be increased, while the latter is calculated to remove any gastric debility, and to impart a general tone to the body: there is no doubt but that Bitters, from their invigorating influence upon the primæ viæ, (see page 78) increase the effects of remedies whose operation is connected with changes in transitu, or with absorption, as in the exhibition of certain diuretics;^[248] they also frequently render the stomach and bowels more susceptible of bodies that act by impression, as purgatives, emetics, &c.

We may discover the operation of such a principle in some of the more active compounds presented to us by nature: many herbs owe their efficacy to a cause of this kind. Elaterium, as I have ascertained by experiment, contains a purgative element, sui generis, (Elatin) and a bitter principle, which in itself is quite inert, and yet its presence in the compound renders the alimentary canal more susceptible of the impression of the active ingredient, and therefore increases its force. See Extract. Elaterii. The history of Senna will afford some interesting facts in farther elucidation of this subject; the leaves of this plant, like Elaterium, appear to contain an active principle, in combination with a bitter, which latter ingredient, although destitute of purgative properties, considerably increases those of the former; for if this be removed, as happens when Senna is transplanted into the south of France, the purgative principle is weakened, but may be again restored by the artificial addition of some bitter extractive. The fruit or pods of Senna^[249] contain only the purgative principle, and are therefore comparatively feeble, unless the defect be compensated by art. Dr. Cullen has observed that a much smaller quantity of the leaves is required for a dose if they be infused in company with some bitter plant; and it has been found that the watery infusion of Rhubarb is rendered more purgative by the addition of Calumba.

The experiments of Seguin have established beyond all doubt that the active principle of vegetable astringents is a peculiar element, to which the name of Tannin has been given; but the efficacy of this ingredient is undoubtedly enhanced by the presence of the gallic acid with which it is usually associated, although this acid, when separated from the native combination, is incapable of producing the least astringent effect; that 154peculiar flavour which we so commonly experience in unripe fruits, and which we designate by the term acerbness, is the result of a combination of the astringent principle with some vegetable acid. The relative sweetness of sugar, when in different degrees of purity, depends upon the operation of the same law of combination; pure sugar, as Dr. Mac Culloch has very justly observed, however paradoxical it may appear, is not so sweet as that which is impure; the sweetness of melasses, compared with that of refined sugar, is too well known to require more than a bare mention; the vegetable extractive matter in this case, increases the effect of the saccharine principle with which it is combined; for the same reason grapes, differing very materially in their proportion of saccharine matter, may seem to the taste equally sweet, and such in fact is the case on comparing the luscious grapes of Spain, with the Chasselas of Paris; and yet the vinous produce is entirely different, the result of the one being a sweet and luscious wine, while that of the other is hard and dry, because, in truth, these grapes contain very different proportions of sugar; and however powerfully the extractive matter may modify the effects of this principle upon the palate and organs of taste, it cannot alter the quantity of alcohol resulting from its fermentation.^[250] Crystallized sugar also appears less sweet to the taste than loaf sugar, but this may depend upon the different state of aggregation, and, consequently, the different degrees of solubility possessed by the sugar in these two forms.

In some cases, the addition of certain bodies will induce the absorbents to admit and carry into the circulation remedies which, in a more simple state, they would reject as injurious; this position is supported by the fact of mercury being more readily absorbed when in combination with animal matter, see Ung: Hydrarg: and it is probable that iron, in the form of a tanno-gallate, will be more acceptable than when presented in a more purely mineral state: see Ferri Sulphas.

Does it not therefore appear from the preceding remarks, that certain elements exist in the composition of vegetable remedies, as furnished by nature, which, although individually inert, confer additional strength and impulse upon the principle of activity with which they are associated.^[251]

155The solutions of saline cathartics appear likewise to gain an accession of power and celerity of operation by impregnation with Carbonic acid gas, depending probably upon the intestines thus receiving a degree of distention favourable to the action of the salt, (19, 23.) Certain it is that the operation of emetics, as well as that of glysters, is materially increased by the stimulus of distention.

In enumerating the methods to be adopted for increasing the energies of a remedy, by rendering the system more susceptible of its action, it is right to know that, under certain circumstances, Venesection deserves a distinguished rank amongst the Adjuvantia. The fact is strikingly discovered in the exhibition of Mercurial^[252] Preparations, and some other alterative medicines. Whether the “Vis Conservatrix,” which Nature, when in a state of health and vigour, opposes to the admission of poisonous substances into the circulation, be overcome by blood-letting, is a question which I shall leave others to decide; but thus much reiterated practice has taught me, that the system in a strong and healthy condition frequently is overcome the moment the stomach becomes deranged, the circulation languid, or the general tone of the system impaired. I have frequently seen this during my Hospital practice: if a patient who has been using mercurial friction, or taking the preparations of that metal without effect, be transferred into a close and unhealthy ward, his appetite soon 156fails, the tongue becomes furred, and the system instantly yields to the influence of the remedy. Nauseating doses of antimony^[253] frequently repeated, or the accidental supervention of any disease of debility, will be attended with the same phenomena. My practice has also afforded me an opportunity of appreciating the debilitating effects of despondency in a case of this description; a patient had been taking mercurial medicines, and using frictions for a considerable period, without any apparent effect: under these circumstances he was abruptly told that he would fall a victim to his disease; the unhappy man experienced an unusual shock at this opinion, and in a few hours became violently salivated.^[254]

Venesection, moreover, increases the effects of cathartic medicines. I have often noticed this fact in contending with a plethoric diathesis; whenever the bleeding preceded the purgative, the effects of the latter have been uniformly more speedy and considerable; in obstinate constipation the same fact has been observed, and mild remedies have been known to act more powerfully, when preceded by blood-letting, than potent ones have when exhibited antecedent to it. Venesection has certainly an extraordinary power in awakening the susceptibility of the primæ viæ to remedial impressions; in some diseases, as in the Cynanche Trachealis, or Croup, so great is the insensibility of the stomach, that Emetics frequently fail in their effects; and Dr. Hamilton has given as much as a hundred grains of Calomel in the twenty-four hours: in such cases previous venesection affords most extraordinary assistance. Dr. Fothergill also remarks that emetics are more beneficial after bleeding, (Dissert. Med. Inaug. de Emet. usu.) The effects of Bark, Steel, and other tonics, are certainly influenced in the same manner; whether in any case it may be prudent or judicious to have recourse to such a practice, is a question not immediately connected with the present inquiry.

Limited must have been the experience of that practitioner who has not frequently witnessed the utility of Venesection in producing a state of system favourable to the operation of various remedies. In acute diseases, how frequently does an opiate succeed in allaying irritation after copious bleeding, which could not be made to occasion any beneficial influence 157previous to that operation? In Pneumonia I have repeatedly seen such a plan of treatment act like a charm upon the patient.

Purgatives also awaken the susceptibility of the body to mercurial impressions, and it is remarked by Dr. Chapman that this practice affords a resource which rarely disappoints the practitioner. This class of remedies moreover seems capable of exalting the efficacy, and indeed of accelerating the benefit to be derived from many alteratives, when administered previous to the exhibition of these latter substances; the advantages of a course of Steel medicines are undoubtedly increased by such means. The febrifugous and antiseptic properties of diluted muriatic acid (see Form. 145.) are inconsiderable, unless its exhibition be accompanied with cathartics. I beg to refer the practitioner to some cases published by me in the Medical and Physical Journal for December, 1809, in further illustration of these views. Experience enables me also to state that Diuretics are considerably assisted by similar means, having many instances in my case book of the failure of these agents before, and their successful operation after, the exhibition of a cathartic. Dr. Darwin observes that “Absorptions are always increased by Inanition,” and in support of this position refers to the frequent advantage derived from evacuations in the cure of ulcers. I have certainly seen obstinate sores in the leg cured by small and repeated bleedings. Dr. Chapman arrives at the same conclusion, although by a different train of reasoning; he states that the blood-vessels and absorbents^[255] are to a certain extent “antagonising powers:” instructed by this obvious fact, we ought, says he, in the exhibition of diuretics to regulate the state of the system by interposing purgatives, or even venesection, as the state of the circulation may indicate.

Emetics also, in certain conditions of the system, would appear to render the stomach more sensible to the impression of other remedies; Dr. Eberle, of Philadelphia,^[256] has remarked such an effect with respect to the administration of the Peruvian Bark.

Change of Diet and of Habits may be also classed amongst the Ajuvantia, but the young practitioner must be warned that he is not to exercise his Caduceus as Sancho’s Doctor did his wand. I have seen a young disciple of Esculapius so vex his patient, that his food became more nauseous to him than his medicine, and I verily believe his Physician was more irksome than his disease. It was well observed by Dr. Percival that the prejudices of the sick should never be contemned with wantonness, or opposed with harshness; for, silenced by authority, they will operate secretly and forcibly on the mind, creating fear, anxiety, and watchfulness. And with regard to diet it may be here stated, that no function of the body is so materially influenced by mental impressions as that series of actions constituting what is termed Digestion—the unexpected communication of any distressing event destroys the keenest appetite,^[257] and converts the sensation of hunger into one of disgust at the bare 158idea of food: a fact which did not escape the penetrating eye of our immortal Shakespeare, for he represents Henry dismissing Wolsey from his government with these words—

If feelings of disgust are excited by the repast, the stomach will never act with healthy energy on the ingesta; and in cases of extreme aversion, they are either returned, or they pass through the alimentary canal almost unchanged: on the other hand, the gratification which attends a favourite meal is in itself a specific stimulus to the organs of digestion, especially in weak and debilitated habits. Dr. Merriman has lately communicated to me a case which affords a striking illustration of the powerful influence of the mind upon these organs: a lady of rank labouring under menorrhagia, suffered with that irritable and unrelenting state of stomach which so commonly attends that disease, and to such a degree that every kind of aliment and medicine was alike rejected: after the total failure of the usual expedients to appease the stomach and procure relief, she applied to Miss Prescott, and was magnetised, when she immediately, to the astonishment of all her friends, ate a beef steak, and continued to repeat the meal every day for six weeks, without the least inconvenience! but the disease itself, notwithstanding this treacherous amnesty of the stomach, continued with unabated violence, and shortly afterwards terminated her life.

The diet of a sick person ought never to combine too much nutriment in too small a space;^[258] when so given it will even in health be followed by fermentation instead of digestion; and although we may admit the expediency of that domestic maxim, “a little and often,” yet this is to be received with limitation; no one, for instance, who possesses any philosophical knowledge, will adapt his practice to the notions of Sir William 159Temple, who asserted that “the stomach of a valetudinarian was like a school-boy, always doing mischief when unemployed,” and that we should therefore not allow it any interval of repose: to this I answer, that the conversion of aliment into blood is effected by a series of elaborate processes, several of which are only perfectly performed during the quiescence of the rest: it would seem, for instance, that the process of chylification is incompatible with that by which the first changes are produced in the stomach; this is evident from the well-known fact, that our appetite for food ceases when the former process commences, although the repast should, at the time, have been insufficient to satisfy the craving of nature; whereas, in diseases of imperfect, or depraved digestion, as in Diabetes, Tabes Mesenterica, &c. we find that the appetite for food is never satisfied by the most nutritive meals. It merits notice also, that whenever the stomach be called into action during the assimilating stages of digestion, the process will, in weak persons, be much disturbed, if not entirely suspended. These views have long since confirmed me in the propriety of treating mesenteric affections in a manner very different from that which is generally pursued; and I may add that the result has been very satisfactory. The plan to which I allude, consists in enforcing longer intervals between each meal, which should be scanty, and in quantity short of what the appetite may require; in this way are the unwilling absorbents induced to perform their duties with greater promptitude and activity; but it is a practice which, from the extreme anxiety of friends and relatives, the feelings of craving and hunger expressed by the patient, and the mistaken but universal prejudice respecting diet, it is always painful to propose, and generally impossible to enforce; where, however, circumstances have given a full and unreserved controul, the advantage of the plan has been most decisive.

There is still another remark which I am desirous of offering, in this place, on the subject of Diet; viz.—that in all cases of feeble or imperfect digestion, the Valetudinarian ought never to take his principal meal in a state of fatigue—and yet let me ask, whether there is a habit more generally pursued, or more tenaciously defended? Aye, and defended too upon principle—the invalid merchant, the banker, the attorney, the government clerk, are all impressed with the same belief, that after the sedentary occupations of the day, to walk several miles to their villas, or to fatigue themselves with exercise before their dinner, or rather early supper, will sharpen their tardy stomachs, and invigorate their feeble organs of digestion. The consequence is obvious,—instead of curing, such a practice is calculated to perpetuate, and even to aggravate the malady under which they suffer; by calling upon the powers of digestion at a period, when the body is in a state of exhaustion from fatigue. Often have I, in the course of my practice in this town, cured the Dyspeptic invalid, by merely inducing him to abandon so mischievous a habit.

A. By Mechanically separating, or Chemically neutralizing, the offending Ingredient.

The scientific physician, from his knowledge of the chemical composition of a medicine, and of the principles upon which its different qualities depend, is enabled to remove or render inert the element which imparts to it a deleterious operation; thus it has been found that the peculiar principle in the Spanish Fly, which so frequently irritates the urinary organs, is soluble in boiling water; ebullition in water therefore offers the means of depriving it of the power of thus acting upon the kidneys, while it does not effect any alteration in its vesicatory properties. It is upon the same principle that many vegetable substances of a very acrid nature, become harmless by boiling, or by chemical manipulation, and some of them might even in times of scarcity and want, be introduced as wholesome and nutritious articles of diet. The experiments of Westring shew that the bitterness of the Lichen Islandicus may be entirely removed by maceration in an alkaline ley, and a tasteless, but highly nutritious fecula be thus obtained; in the same manner the Æsculus Hippocastanum (Horse Chesnut) may be deprived of its bitterness, leaving a residuum which will afford a kind of bread; and according to Parmentier (Recherches sur les vegetaux nourissans,) excellent starch may be also made from it. Dr. Darwin observes, that if the roots of White Bryony be rasped into cold water, and agitated with it, the acrid juice of the root along with the mucilage will be dissolved, or swim in the water; while a starch perfectly wholesome and nutritious will subside, and may be advantageously used as food; by a similar species of address the French prepare from the acrid Arum the harmless, but highly prized cosmetic, called Cyprus powder.

There are many substances which receive a much pleasanter mode of operation by having their solubilities increased or diminished; thus the griping occasioned by several drastic purgatives is obviated by the addition of some alkali: and the nauseating tendency of Camboge, which arises from its too easy solubility, is prevented by incorporating it with some insoluble body; as in the Pilulæ Cambogiæ Comp: but the farther consideration of this question will be resumed in the fourth section of the Analysis. (iv. c.)

Numerous attempts have been made to correct the inconvenient effects of Opium, such as nausea, head-ache, and costiveness, by removing the resinous element, upon which such evils have been supposed to depend, and we have accordingly been at different times presented with a variety of Formulæ for the accomplishment of so desirable an object; (see Opium). More recently, opium has been discovered to possess two active principles, viz. Morphia and Narcotine, which would appear from the researches of M. Majendie to exert very different powers upon the animal system; the 161former imparting to opium its soporific, the latter, its exciting property; whence it is proposed to remove this latter principle in order to render the operation of opium milder, and at the same time to divest it of those objectionable properties which so greatly limit its medicinal utility. See Opium.

B. By adding some substance capable of guarding the stomach, or system, against its deleterious effects.

The virtues of our most important remedies are frequently lost, or much invalidated, for want of proper attention to the circumstances comprehended in this section. It may be almost admitted as an axiom that whenever an ALTERATIVE medicine acts with violence upon the primæ viæ, its energies are uselessly expended, and the object of its exhibition defeated. So again, Diaphoretics, Diuretics, and many other remedies, suffer a diminution in their effects, whenever they stimulate the stomach or bowels to excess. Guaiacum thus loses its anti-arthritic, Squill its diuretic, and Antimony and Ipecacuan their diaphoretic, virtues; the action of these substances may therefore require correction, and a medicine must be selected capable of fulfilling that intention. Opium has very extensive powers as a corrigent. See Form. 57, 100, 106, 110. Dr. Mead combined alkaline salts, when intended to act as diuretics, with opium, in order to prevent their action upon the bowels. Acetate of Lead, when administered in cases of hæmopthysis, or uterine hemorrhage, should also be guarded by the addition of a small portion of the same narcotic. Dr. Sutton, of Greenwich, has lately written a paper to shew, that where we wish to limit the operation of an emetic to the stomach, and to prevent its action on the bowels, we should add five or six drops of laudanum to the emetic draught, which in his experience has answered the purpose in question.^[259] The griping and nauseating tendency of some remedies receives correction by the addition of Aromatic stimulants, or Essential oils, (69, 71, 78, 84, 85, 92,) or by small portions of a corresponding tincture, (70, 76.) It has been already stated, that the griping from Senna and resinous purgatives may be, in a great degree, obviated by the addition of alkalies; it remains to be observed, that the same remedies are also mitigated in severity, by saline purgatives, (77.) I learn from Sir Henry Halford, that in his practice he has found the addition of Extract of Hyoscyamus render the operation of the compound extract of Colocynth much more mild, and no less efficacious. Of the value of such a combination, I am myself able to bear ample testimony. Alum is corrected in its tendency to disturb the bowels by the addition of Nutmeg, (Form. 53,) or some aromatic; and the drastic operation of Colocynth may be mitigated by trituration with Camphor. There are several substances which are deprived of their acrimonious qualities by trituration with mucilage, milk, barley-water, &c. The tendency which mercurial preparations possess of affecting the bowels, is, with the exception of Corrosive Sublimate, corrected by Opium, but the acrid operation of this latter salt is more securely guarded against by the decoction of Guaiacum or Mezereon, or by the plentiful exhibition of mucilaginous drinks and broths. In certain diseases of the uterus and vagina, astringent lotions are indicated, but it may happen, as in the cauliflower excrescence, or in the oozing tumour 162of the labium, that such applications are too irritating; in such cases the effect of the lotion is corrected by the addition of mucilage. The enfeebling influence of Digitalis, Tobacco, and some other narcotics, is successfully opposed by aromatics and stimulants. It has already been stated that several attempts have been made to correct the operation of Opium by the application of mechanical and chemical resources; it would, however, appear that, for obviating its effects upon the intestinal excretions, the judicious addition of some purgative will offer the most effectual corrigent; and, according to my own experience, the Aloetic preparations are to be preferred upon such an occasion, as in Form. 11, 12, 13. In some cases, I have found that a combination of the watery infusion of Opium with some bitter, will secure the narcotic virtues without those consecutive effects upon the alimentary canal, which we are always so desirous to obviate; the Decoctum Aloes compositum also furnishes upon such an occasion a very appropriate adjunct. Let us remember that one of the effects of opium is to paralyse, for a time, the muscular fibres of the intestines: now experience has taught us that the remedies above directed have a peculiar tendency to augment the peristaltic motions of the primæ viæ. Upon the same principle the addition of calomel will prevent the paralysing influence of this narcotic upon the biliary functions. I have known several patients who could never take opium unless in such a form of combination.

In general, a formula contains but one corrigent; but circumstances may occur, where two different ingredients are required to obviate two very different effects, as in Form. 16, in which the Nitric acid is introduced for the purpose of counteracting the deleterious effects of the opium upon the nervous system, while the Aloetic preparation is calculated to obviate its particular tendency upon the alimentary canal.

Sometimes the unpleasant or perverse operation of a medicine may be obviated by changing the form of its exhibition, the period at which it is taken, or the extent of its dose; Dr. Cullen, for instance, found that the nauseating operation of Camboge might be obviated, by repeating small doses at short intervals. (89.)

Before quitting the present subject, it deserves notice, that there is frequently a chemical condition of the stomach that may interfere with the mild operation of a medicine, and may therefore require consideration: this is particularly exemplified in the action of those antimonial preparations which are liable to become emetic and drastic by the presence of an acid; it is, for this reason, very eligible to guard such substances with antacid adjuncts. See Antimonii Sulphuretum, and Form. 125, 128. There is also, upon some occasions, an irritable state of the primæ viæ depending upon a deficient secretion of mucus, which renders even small doses of any active medicine mischievous; mucilaginous decoctions in such a case will offer the readiest corrigent; see Scammonia.

The vinous infusion of Colchicum appears to act more violently when acid is present in the stomach; small doses of Magnesia may therefore precede, and accompany its exhibition, with advantage.

A. By uniting those substances which are calculated to produce the SAME ULTIMATE RESULTS, although by totally different modes of operation.

It has been already stated, (page 152), that we may frequently combine substances together whose modes of operation are dissimilar, with considerable advantage, provided they be not physiologically incompatible with each other. We may illustrate this subject by a reference to the operation of purgatives; a series of medicinal substances may be produced, each of which has the property of exciting catharsis, but by a very different mode of action; one for instance stimulates the muscular fibres of the intestines; a second acts upon the exhalant vessels, and mucous glands; and a third exerts its influence upon the neighbouring organs, so as to produce an increased flow of their secretions into the bowels; but since such modes of action are quite compatible with each other, they may be simultaneously established, not only without any loss of efficacy, but with the most decided advantage; suppose, for instance, we administer a substance which, either from its insolubility or peculiar nature, acts exclusively upon the muscular fibres of the alimentary canal, its peristaltic motions will be undoubtedly thus increased, and the contents of the bowels evacuated, but the operation will be slow, and probably accompanied with considerable tormina; now it is evident that if to such a remedy we add those which can produce an increased flow of serous fluids, the effect will be both quicker and easier. The infusion of Senna is thus quickened and corrected by Soluble Tartar. In the same manner various substances included in the class of diuretics, which, although different, still if they be not adverse in their operation, may be conjoined; Digitalis and Potass are not similar, nor are they incompatible, for while the alkali, through the medium of the circulation, stimulates the secreting organs of the kidneys, the foxglove may, by its sympathetic action, rouse the energy of the absorbents. In the administration of diaphoretics we shall frequently derive additional force, as well as certainty, by combining those which act by relaxing the cutaneous emunctories, with those which prove diaphoretic by imparting a general increase of momentum to the blood.

B. By combining Medicines which have entirely different powers, and which are required to obviate different symptoms, or to answer different indications.

Arrangements constructed upon this principle constitute some of the most valuable remedies with which we are acquainted; they are in general extemporaneous, because their value depends upon their being varied and modified according to the symptoms and circumstances of each particular 164case. The following general elucidation of the subject may serve to demonstrate the nature and importance of such combinations.

Purgatives with Antispasmodics. The practice suggested by Drs. Stoll and Warren, in the treatment of Cholica Pictonum, affords a striking example of the expediency of combinations of this nature. It is found in that disease, as well as in others attended with spasmodic constriction of the intestinal canal, that purgatives produce no effects unless the spasm be allayed by combining them with Opium, (see Form. 71, 75, 76,) it is from such a cause that the purgative so popular with tailors and shoemakers, and which consists of Aloes with Sagapenum or Galbanum, affords such prompt relief in the spasmodic cholic to which they are subject.

Purgatives with Tonics. In the exhibition of cathartics how frequently it occurs in practice that the patient’s strength will hardly allow the evacuation; in such a case the addition of steel as a roborant (Form. 72, 92, 93,) or even of æther, or ammonia, as a diffusible stimulant, is strongly indicated: the Cheltenham waters offer a natural combination of this character. So again in the cure of dropsy we have often two indications to fulfil—to evacuate the water, and to support the strength of the patient; hence the necessity of combining brisk and stimulating purges, such as Scammony, Jalap, &c. with active tonics, (83.) In the treatment of amenorrhæa the same medicinal arrangement is not unfrequently indicated.

Purgatives with Mercurial Alteratives. In habitual costiveness, where there appears to be a deficiency of bile, a combination of Pilula Hydrargyri, with certain Aloetic compounds, may prove serviceable; for while the latter remedy will, in the absence of bile, supply to the intestines a congenial stimulus, the former will tend to restore the bilious secretion by its influence upon the hepatic system. See Form. 79, 81.

Purgatives with Diaphoretics. This combination of effects is often useful in practice, but it is desirable that the latter should not be established until the operation of the purgative upon the bowels has subsided. This is accomplished by certain doses of Tartarized Antimony in conjunction with some purgative. The Pulvis Aloes Compositus of our Pharmacopœia produces a somewhat similar effect.

Diaphoretics with Tonics. How frequently is the practitioner desirous of determining to the skin, and at the same time of supporting the strength of the general system? in the progress of a continued fever we are repeatedly called upon to fulfil such indications. Dr. Bree^[260] also observes that “in the exhibition of Diaphoretics the addition of a bitter infusion, or tincture, is frequently proper; for the stomach should be gently excited and strengthened during the use of a diaphoretic draught.” On the other hand, Tonics not unfrequently require the aid of a diaphoretic; for instance, in the cure of Cynanche maligna, the use of bark is indicated; but if the skin be hot and dry, it should be accompanied with a diaphoretic. See Form. 126.

Antispasmodics with Tonics, or Narcotics. Under the history of Antispasmodics, (page 78) it is stated that there are certain bodies which seem to exert an absolute control over inordinate muscular action, from whatever general cause it may have arisen; in administering such remedies, 165however, the intelligent practitioner will not overlook the peculiar condition of the system in its relations to the disease; where debility is present, the Antispasmodic will be usefully combined with a Tonic; and, in certain morbid states of the nervous system, with a Narcotic.

Astringents with Diaphoretics. Dr. Fordyce has observed, that combinations of this kind are often indicated in cases of Diarrhœa, where it is necessary to astringe the vessels of the intestines, and at the same time to relax those of the skin; such an indication, he says, may be fulfilled by exhibiting Tormentil root, or any other vegetable astringent, with Ipecacuan.

Astringents with Narcotics, and Absorbents. It has been already observed, that in a Diarrhœa, depending upon the influx of acrid fluids into the intestines, there are three modes of treatment by which the malady may be obviated, viz. by a narcotic, diminishing the irritability of the intestines; by an astringent, restraining the serous excretion; and by an absorbent, neutralizing the acrid matter. As the modes of action are not incompatible with each other, they maybe simultaneously established with the greatest advantage. See Form. 52.

Astringents with Tonics. A combination of certain medicines belonging to these two classes is frequently indicated; in the treatment of passive hemorrhage, we have to astringe the bleeding vessels, and, at the same time, to cure the hemorrhagic diathesis by remedies which are capable of restoring the general tone of the system. In the treatment of the chronic and humid coughs of old persons, I have very frequently witnessed the beneficial union of the warm and stimulating influence of Myrrh with the astringent effects of Sulphate of Zinc. Form. 69 presents the combination which I have usually adopted with success on such occasions.

Diuretics with Tonics. As Dropsy is frequently associated with great debility, the practitioner should combine his diuretics with some tonic medicine; but in forming a judgment upon the case he must be guided by those precepts which have been laid down under the consideration of Diuretics at page 97. See Form. 114.

Diuretics with Aromatic Stimulants. Such a combination will be found advantageous in those cases where the powers of the system require to be excited by more prompt measures than those afforded by the agency of tonics. Ethereal preparations, with Squill and other stimulating diuretics, are well calculated upon such occasions to afford valuable assistance. Form. 101–116.

Tonics with Diffusible Stimulants. In the cure of dyspepsia, we frequently require a remedy, for the purpose of obviating debility, that is more sudden in its action, and prompt in its effects, than that of a bitter tonic, whose operation is almost imperceptible; while the case may at the same time stand in need of that permanent increase of tone, which the latter remedy can alone supply; such an indication therefore must be fulfilled by combination. Form. 40, 42.

Tonics with Purgatives. In the exhibition of tonic medicines it is frequently essential to accompany their operation with purgation; in intermittent fevers, for instance, when attended with a redundant secretion of bile, or any obstruction of the viscera, the bark must be given in combination with some laxative, for which purpose Boerhaave has recommended Muriate of Ammonia; Mead, Rhubarb; whilst in many cases, experience 166suggests the propriety of selecting some of the warmer cathartics, especially the Alöetic: and I shall take this opportunity to observe, that notwithstanding the opinion so strongly expressed by Sydenham, that “to add any thing to the bark argues either ignorance or craft,” the most respectable testimony may be adduced to demonstrate the great advantages which have arisen from the various combinations of this heroic remedy. Sir George Baker has said that “there is less of reason than of severity,” in the above remark of Sydenham; for that it was found in the cure of the intermittent fever, which he describes, that, according to circumstances, sometimes the Virginian snake root, and in other cases Myrrh, were added with propriety and advantage; and, according to the experience of several practitioners, a drachm of the rust of iron, and the same quantity of the powder of black pepper, added to each ounce of bark, were the means of subduing the most inveterate agues. Formula 44 presents a combination, which we learn from Dr. Petrie’s letter to Sir George Baker, constitutes a celebrated Dutch remedy for an ague, and which was tried with success in the hospital at Lincoln, in those obstinate intermittents which prevailed in the year 1781. Hillary speaks of an epidemic intermittent at Barbadoes, in which the bark was of no avail, unless combined with saline remedies, or some of the tonic bitters. Dr. Barton has stated that Bark combined with Mercury in a small proportion, is one of the best remedies for removing the swelling of the spleen after an intermittent.

Expectorants with Diffusible Stimulants. We have seen that expectorants may be usefully associated with tonics; it sometimes occurs that these remedies require the addition of some diffusible stimulant. In certain states of Peripneumonia notha, where the powers of life are ebbing, and the lungs become inundated with viscid mucus, I have experienced the value of a combination of some stimulating expectorant and ammonia.

Antacids with Tonics. In the cure of cardialgia we have obviously two indications; to neutralize the offending acid by some chemical agent, and to correct the morbid state of the digestive functions by some appropriate remedy. See Form. 152. The same observation will apply in the treatment of certain cases of chlorosis, where cardialgia is not unfrequently a very vexatious attendant, and solicits the union of emmenagogues with antacids, or absorbents, as in Form. 99.

Lithonthryptics with Narcotics. As a palliative in calculous irritation, the union of alkalies and opium proves a valuable resource. Henbane may likewise be advantageously combined with a Lithonthryptic; for, be it remembered, that few narcotics are more efficacious in allaying nephritic irritation. (Form. 156.) We have also frequently two important indications to fulfil in the treatment of urinary concretions; where the lithic acid diathesis prevails, it will be necessary to neutralize any acidity in the first passages, and at the same time to regulate the functions of the skin; we have moreover to give tone to the digestive organs; so that, in such cases, the art of medicinal combination is well calculated to extend our resources.

In the formation of these compounds we should rarely attempt to fulfil more than two indications, although cases may occur in which it will be eligible to assail the disease with an engine of triple powers, as exemplified by Form. 52 .

In constructing, however, such complex arrangements the practitioner must of course take care that he does not fall into the error of Contraindication, 167and combine substances which possess properties essentially different, and which are at variance with, or directly opposed to each other; it is an error of the most serious description, and unfortunately is one of too common occurrence in the lower walks of medical practice; “crimine ab uno disce omnes.” I lately met with a country practitioner who, upon being asked by a lady whom he attended, the intention of three different draughts which he had sent her, replied, that one would warm, the second cool her, and that the third was calculated to moderate the too violent effects of either; thus it is that discredit and contempt fall upon the use of medicines, which ought only to attach to the ignorant pretenders, or designing knaves who administer them.

Having, in the commencement of this inquiry, stated that all the principles of combination, capable of practical application in the construction of extemporaneous formulæ, are exemplified in the composition of the various productions of Nature, I shall conclude the present section by shewing, that many of our most valuable vegetables owe their useful properties to the joint operation of the several distinct and different ingredients which enter into their composition. How many substances does Nature produce in the vegetable kingdom, in which the permanent tonic quality of bitterness exerts its influence in union with the transient stimulating powers of an aromatic principle? indeed there is a series of vegetable remedies of this kind: commencing with those that are simply bitter, we gradually proceed through the different species, each blending as we advance an increasing proportion of aroma, until we arrive at those in which the aromatic quality greatly preponderates. Peruvian Bark may be said to combine within itself the properties of bitterness, astringency, and aroma; a fact which suggested the probability of our being able to produce an artificial compound that might emulate the effects of Cinchona, and to a certain extent the idea appears to have been realised; for we are told by Dr. Cullen, that he frequently succeeded in the cure of an intermittent by a combination of Oak Bark and Gentian, when neither bitters nor astringents, separately, produced the least impression; and I am informed by Dr. Harrison, that in the Horncastle Dispensary, of which he was for many years physician, he never employed any other remedy for curing the ague of Lincolnshire than equal parts of Bistorta (astringent) and Calamus Aromaticus (bitter and aromatic), neither of which plants, individually, ever produced the least benefit in such diseases. Berzelius attempted to produce a compound of this description by adding to the bark of the Ash some Tormentil root and Ginger; and he observes that it acted as an excellent tonic, and that according to the experiments of his friends it seemed to cure quartan agues.^[261] In the aromatic barks and woods, such as those of the Canella, Orange-peel, Sassafras, &c. the aromatic principle^[262] is combined with a bitter ingredient; a union which proves of singular service in the formidable bowel complaints so common in tropical climates.

The great superiority of the hop, as an ingredient in our malt liquors, depends upon the fact of its containing within itself several distinct and independent elements of activity, which the other bitter herbs that have at 168different times been employed as its substitute, do not possess. The philosophy of its operation may be adduced as a striking illustration of the present subject; first, then, it contains a bitter principle, which imparts to the beverage a tonic quality and an agreeable flavour; while at the same time an aromatic ingredient adds a warm and stimulant property and modifies the bitterness; the hop, moreover, contains an astringent ingredient (Tannin and Gallic Acid), the effects of which are to precipitate the vegetable mucilage, and thus to remove from the beer the active principle of its fermentation; every attempt therefore to substitute an ordinary bitter for that of the hop must necessarily fail, unless a compound can be so artfully constructed as to contain in due proportions, the principles of bitterness, astringency, and aroma. Quassia must therefore necessarily prove but a sorry substitute; it will impart bitterness enough, but it will not be modified by agreeable aroma; and as it contains no astringent principle, it will fail in precipitating the vegetable mucilage, or gluten; in consequence of which the beer so manufactured will be in a perpetual state of fermentation until it is entirely spoilt.^[263] Rhubarb is another medical plant which may be brought forward in elucidation of the analogies subsisting between natural and artificial combinations; in this case Nature has presented us with a singular and most important union of medicinal powers,—that of an astringent, with a cathartic property! virtues, which we might, without the light of experience, have pronounced to be incompatible with each other; and yet we find that in this instance the property of astringency never interferes with, or opposes the purgative force, since the former does not display itself unless the substance be administered in small doses; or, when given in larger ones, not until it has ceased to operate as a cathartic.

IV.
TO OBTAIN A NEW AND ACTIVE REMEDY NOT AFFORDED BY ANY SINGLE SUBSTANCE.

A. By combining medicines which excite different actions in the Stomach and System, in consequence of which New, or modified results, are produced.

This constitutes by far the most obscure part of the subject of medicinal combination, and must ever continue so until we become better acquainted with the laws which govern the action of medicinal substances upon the living system. That the most valuable effects, however, are really produced by such arrangements, we have the testimony of long experience, and examples are furnished in the valuable and well-known operation of many officinal preparations; thus the “Pulvis Ipecacuanhæ compositus” contains as its active elements, Opium and Ipecacuanha; and yet, in well regulated doses, it neither possesses the narcotic operation of the former, nor the nauseating effects of the latter; they appear to be mutually lost, and converted into a powerful diaphoretic: so again, the emetic operation 169of Sulphuret of Antimony, and the specific influence of Calomel, are changed by combination with each other, giving rise to a remedy eminently distinguished for its powers as an alterative. Dr. Bree observes that Tincture of Squills combined with Extract of Henbane, and the Nitric Acid, have been proved by much experience to be expectorant and sedative in a paroxysm of asthma, although each article, uncombined, had been given without success. See Form. 139. The efficacy of Hemlock, in quieting Pulmonary irritation, has been frequently adverted to in the course of this work; I have to state, in this place, that its value, on such occasions, is generally enhanced by combination with Ipecacuanha.

It is probable that many of our natural remedies owe their efficacy to the results of a similar species of combination. In the fourth edition of this work it was stated that, according to the assertion of Dr. Chapman, “Kino, when administered in union with Calumba, constituted a pretty certain, and powerful purgative;” since the publication of this fact, I have investigated what, if true, would appear to be a most extraordinary anomaly in the philosophy of medicinal combination, and I find that the statement of Dr. Chapman^[264] is not borne out by experiment. That we might arrive at a just conclusion upon this subject, I requested the assistance of my friend Dr. John Davy, whose character for experimental accuracy, and whose situation as Superintendant of the Medical Division of the General Military Hospital at Chatham, seemed to point him out as a person peculiarly adapted for such an inquiry; the result of his trials does not establish that of the experiments of Dr. Chapman, but on the contrary it seems to prove, that neither Kino nor Calumba, when taken separately, has a constipating effect, and that in the form of powder (especially the Calumba) each has an aperient quality, which is not increased by exhibiting the two medicines together in a state of mixture. The trials from which these inferences are drawn were made on different individuals in tolerable health, and they were repeated more than once; in some cases they were given separately, and in others, mixed together, in doses varying from a scruple to a drachm of each.

B. By combining Substances which have the property of acting chemically upon each other; the result of which is the formation of new Compounds, or the decomposition of the original Ingredients, and the developement of their more active Elements.

A. The Formation of New Compounds.

It is not necessary to extend our researches beyond the range of the Pharmacopœiæ,^[265] to collect a variety of interesting and important examples, in illustration of this division of our subject; if we require a striking example of the agency of chemical combination in destroying the identity of the original constituents, and of giving origin to a compound of new powers, it may be exemplified by the well known instance of Sulphate of Potass, a substance possessing but a weak affinity for water, and exerting 170but little energy upon the animal œconomy; whereas the two ingredients of which it consists are distinguished for the extreme eagerness with which they unite with water, and for the caustic activity which they display in their action upon animal matter.

Under this head the class of metals will also present itself to our consideration, all the individuals of which, with the exception perhaps of iron, are perfectly inert and harmless; even arsenic, lead, copper, and mercury, which in certain states of combination constitute some of the most virulent of known substances, exert no action upon the living system, unless they be in union with some other body; but when so united, how valuable do they become, and what various medicinal effects may they not be made to produce.

The Acetic Acid and Ammonia become neutralized by combination with each other, affording a compound of new virtues. Sulphate of Zinc, and Acetate of Lead, when mixed together in solution, decompose each other, and the Acetate of Zinc which is formed, affords a more valuable remedy than either of the former salts, as an application in ophthalmia. The “Mistura Ferri Composita” of our Pharmacopœia offers another example of the same chemical resource. I also beg the reader to refer to the construction of Formula 82, which presents an instance of a purgative draught being produced by combination, in which the original properties of every element are entirely changed. See also Formula 87, the chemical actions of which are more complicated, but no less instructive than the preceding one; the ingredients of the formula are the Carbonates of Soda and Magnesia,—Sulphate of Iron,—Diluted Sulphuric Acid, and Water—and when mixed together, the following decompositions would appear to take place; the free Sulphuric Acid, together with that which exists in the Sulphate of Iron, being just sufficient to decompose the Carbonates of Soda and Magnesia, forms two neutral Sulphates (viz. Sulphates of Soda and Magnesia,) and thereby disengages a volume of Carbonic Acid gas, which not only increases the purgative operation of the new saline compounds, but, by its excess, holds in solution the Carbonate of Iron, which is formed by the decomposition of the Sulphate, and which in that state displays an effect powerfully tonic.

Before we quit the consideration of medicinal compounds as the results of chemical action, it is expedient to remind the practitioner of the essential difference between Mixture and Combination, a difference which affects the medicinal virtues no less than the chemical characters of bodies; it is determined by ample experience, that substances will produce effects upon the living system when presented in a state of simple mechanical mixture, very different from those which the same medicines will occasion when they are combined by the agency of chemical affinity, as is well exemplified in the comparative effects of alcohol as existing in ardent spirits, and in wine (see Vinum); or in the relative powers of Mercury in the Unguentum Hydrargyri of the London College, and the Unguentum Oxidi Hydrargyri cinerei of the Pharmacopœia of Edinburgh, (see Unguent. Hydrargyri); the former of which is a true chemical compound, whereas the latter is a simple mixture of its ingredients.

The accomplishment of such an effect is in many instances the sole object of a pharmaceutical process. It is thus that we obtain pure Citric acid from the juice of the Lemon; Tartaric acid, from Cream of Tartar; Benzoic acid, from the resinous substance known by the name of Gum Benzoin; upon the same principle, the Muriatic and Nitric acids are elicited from the saline compounds in which they exist. Ammonia, in its pungent form, is developed from its inodorous Muriate; and the fixed alkalies are obtained in their caustic state, from the comparatively mild carbonates in which they naturally exist. But a more striking and instructive instance of the effect of chemical action, in developing an active, or useful principle, cannot perhaps be selected than that of the well known stimulant Plaister, composed of Muriate of Ammonia, Soap, and Lead Plaister, in which the alkali of soap enters into combination with the muriatic acid, when the Ammonia, upon which the virtues of the plaister solely depend, is slowly disengaged in the form of gas, producing a powerfully rubifacient and stimulant effect: the “Cataplasma Fermenti,” or “Yeast Poultice,” is indebted for its antiseptic properties to a similar agency, for they do not depend upon any virtue in the ingredients themselves, but upon their decomposition, and the consequent developement of an active element, which is Carbonic Acid. The practitioner unacquainted with the modus operandi of these combinations, would inevitably fall into an error by which their efficacy must be lost; he would hardly apply them as soon as they were formed, nor would he be aware of the necessity of repeating them at short intervals.

The decomposition of Calomel by lime water, forming the well known “black wash” and that of corrosive sublimate in the same fluid, constituting the “aqua phagadenica,” furnish remedies which derive all their peculiar efficacy from the developement of the mercury in different states of oxidation. The reader will find another, and a very striking illustration of the same principle in the history of “Alterative Drops,” under the article “Hydrargyri Oxy-murias.”

A substance separated by chemical precipitation is often a valuable remedy, being in a much more subtle and impalpable form than any body can be rendered by mechanical triture and levigation;^[266] for example, the Carbonate of Lead, (Cerussa), when diffused in water, is according to the experience of our best surgeons, far less active as a topical application than the same substance when produced at once by precipitation from the Sub-acetate of that metal. In some cases, also, the substance obtained by precipitation is in a different state of oxidation from that which is prepared by a different process, see Mist. Ferri Comp: It is a question well worthy of consideration whether a more active preparation of the Antimonial powder might not be formed by obtaining the oxide by the precipitation of Tartarized Antimony.

Many interesting and important illustrations have been lately afforded by an extended knowledge of vegetable chemistry, recent analyses having developed principles of extreme activity from several of our most esteemed plants; thus have Sertuerner and Robiquet succeeded in separating a narcotic 172element from Opium (Morphia); Majendie, and Pelletier, an emetic principle from Ipecacuan, (Emeta); and the last mentioned chemist, together with Caventou, a tonic one from Peruvian Bark, (Cinchonia), the properties and applications of which will be fully explained hereafter, under the history of the different substances which contain them.

It is only here necessary to caution the practitioner against those fallacies into which the captivating theories of the chemist may seduce him; and, if the views which I have offered upon the subject of combination be correct, it will follow as a corollary, that the concentration of an active element must in many cases abridge its powers as a remedy; for although the matter thus removed may individually be quite inert, yet, in combination, it may subdivide the particles of the essential constituent, or modify its solubility, and give impulse and steadiness to its operation; thus the vegetable alkali Quina, although it indisputably constitutes the active matter of bark, will be found inefficacious when separated from it, unless it be rendered soluble by the addition of sulphuric, or some other acid.

C. By combining substances, between which no other chemical change is induced, than a diminution, or an increase, in the Solubilities of the principles, which are the repositories of their medicinal virtues.

The degree of solubility possessed by a medicinal substance may perhaps be regarded by some practitioners as a circumstance of but little or no importance; it will however appear in many cases that it not only influences the activity of a remedy, but, like its dose, goes far to determine its specific operation; indeed, where a medicine is not, in itself, very soluble, the increase of its solubility by any chemical expedient, is tantamount to an increase of its dose.

It is probably owing to the diversity which exists in the solubility of the active elements of certain purgatives, that so great a diversity occurs in their operation; it is, for instance, easy to conceive that a medicine may act more immediately and specially on the stomach, small, or large intestines, according to the relative facility with which its principles of activity enter into solution; that those which are dissolved before they pass the pylorus are quick and violent in their effects, and liable to affect the stomach, as is exemplified by the action of Gamboge, &c. whilst some resinous purgatives, on the other hand, as they contain principles less soluble, seldom act until they have passed out of the stomach, and often not until they have reached the colon. Colocynth has a wider range of operation, since its principles of activity reside both in soluble and in insoluble elements. Aloes again, being still further insoluble, pass through the whole alimentary canal before they are sufficiently dissolved, and act therefore more particularly upon the rectum, by which they are liable to produce piles, tenesmus, and the various effects which so usually attend their operation. The characteristic effects of Rhubarb, Senna, Saline Cathartics, and indeed of all individual substances which compose the class of the purgative medicines, will also admit of a satisfactory explanation from the application of these views. It ought moreover to enable the practitioner, by changing the solubilities of these substances, to change their medicinal effects. Experience shews that this is the fact, and that it may be 173effected either by the intervention of substances that act Chemically; or, by the addition of Ingredients whose operation is entirely Mechanical; thus by combining Aloes with Soap or an Alkaline Salt, we quicken their operation, and remove their tendency to irritate the rectum; the Compound Decoction of Aloes affords a combination of this kind. Gamboge, whose too ready solubility it is an object to obviate, should be intimately incorporated with some insoluble purgative, as for instance Aloes; a formula of this nature was introduced by Dr. George Fordyce, and it has been since simplified and admitted into our Pharmacopœia, under the title of “Pilulæ Cambogiæ Compositæ.” Tartrate of Potash, which, on account of its comparative solubility, has gained the name of Soluble Tartar, acts with corresponding briskness upon the small intestines; but by increasing its proportion of Tartaric Acid, we convert it into a super-tartrate or “Cream of Tartar,” which is a substance characterized by a comparative degree of insolubility, and a correspondent change is produced in the medicinal activity of the salt; its purgative effects are considerably diminished, whilst its diuretic powers are rendered more considerable. We may even extend this experiment by adding to the Cream of Tartar, Boracic Acid, a substance capable of increasing to a certain extent its solubility, when we shall again find that its purgative properties are strengthened in an equal proportion.

It has been observed that a mixture of different saline cathartics is more efficient than an equivalent dose of any single one, a fact which is strikingly exemplified in the prompt and active operation of Cheltenham Salts, in comparatively small doses, as well as in that of sea water. I submit whether this may not in some degree depend upon increased solubility; for it is a law well known to the chemist, that when water has ceased to act upon a salt, in consequence of its having obtained the term of saturation, the solution may still take up another salt of a different kind. I apprehend that an advantageous application of this law might be frequently made in practice, and the energies of a remedy thereby considerably extended.^[267]

Where the active principle of a cathartic is not sufficiently soluble, it is apt to vex and irritate the bowels, producing tormina instead of exciting a free and copious excretion; hence the reason why the operation of resinous purgatives is so commonly attended with griping, and why relief may be obtained by combining them with neutral salts. Thus also Senna, whose virtues reside in extractive matter, is apt by decoction, or long exposure to the air, to act with griping, in consequence of the extractive matter becoming by oxidation, resinous and comparatively insoluble: this effect is best counteracted by the addition of soluble Tartar, that will quicken its action, or by an alkaline salt that will increase its solubility.

It appears then to be established as a pharmaceutical maxim, that the intensity and even specific action of a purgative medicine may be modified or completely changed, by changing the degree of solubility possessed by the principles in which its activity resides.

The application of this principle is highly important in practice, directing us in the choice of the different purgatives, according to the objects which we may wish to fulfil by them, and pointing out safe and easy methods 174by which we may increase, diminish, retard, or accelerate their operation; it thus enables us to construct new and powerful combinations, by imparting to established remedies fresh activity, or by mitigating the acrimony and violence of arrangements in other respects efficacious and eligible.

In the exhibition of solid substances, their mechanical state of division may be capable of modifying their operation, from the influence which this condition must necessarily exert upon their solubilities, although I am by no means disposed to assign to it the importance which Gaubius has ventured to express, “Sunt quæ ruditer pulverata alvum, subtilius vero urinas, aut alios humores movent;” and Ray, speaking of the Asarum (Hist. p. 208) has the following remark—“Quo tenuius est tritum, eo magis urinas movere, minus autem alvum ducere creditur;” and Linnæus^[268] observes that this same plant, when exhibited in the state of very fine powder, uniformly acts as an emetic, but that when coarsely powdered it always passes the stomach, and becomes cathartic. M. Virey has made a similar observation with respect to Hellebore,—“L’Hellebore pulverisé fait vomiter; concassé il purge; et en decoction prolongée, il en devient sudorifique ou diuretique.” I have endeavoured under the article Pulveres to establish some useful precepts upon this subject, to which I beg to refer the reader.

The influence of solubility upon the medicinal energies and specific effects of remedies, may be farther illustrated by a comparative examination of the virtues of the Acetate and Sub-acetate (Goulard’s Extract) of Lead: the former preserves its solubility and integrity under any degree of dilution, while the latter, when slightly diluted with the purest water, in consequence of the carbonic acid diffused through it, gives out a copious precipitate; the acetate therefore is undoubtedly the more immediately active application as a preparation of lead, but it is nevertheless perhaps less adapted to remove inflammation and abate irritation than the turbid mixture of the sub-acetate, since the slow and gradual action which is ensured by the latter is more desirable than the instantaneous operation of the same remedy, applied in a more soluble form: the popular injection for gonorrhæa, consisting of a mixed solution of Sulphate of Zinc and Acetate of Lead, probably owes much of its value to the insoluble precipitate of Sulphate of lead which necessarily takes place, and which, from becoming entangled in the mucus of the urethra, produces a more permanent stimulus than what could have happened from a soluble salt: (Form. 62) thus again the Sulphuret of Antimony, and some other preparations of that metal, of slow solubility, establish a more permanent influence than Tartarized Antimony, and may be preferable to it in cases where immediate and active evacuations are not required.

Of remedies composed of vegetable tonics, the useful application of this principle is also apparent. Thus the addition of alkalies, or lime-water, to the infusions of Gentian, &c. or to the decoctions of Bark, by rendering their extractive and resinous principles more soluble, increase their elegance, and exalt their virtues, (Form. 39, 41,) although this law admits of an important exception to be hereafter explained. A knowledge of this principle likewise offers many useful hints connected with the successful exhibition of active remedies; it points out the medicines which require dilution in order to promote their operation, and those whose too speedy 175and violent effects may be retarded and checked by an abstinence from all potation. Thus, in the exhibition of Diuretics likely to become cathartic or diaphoretic, no liquid should be given for at least an hour after their administration; the same caution applies with respect to the Compound Powder of Ipecacuan, which has a strong tendency to excite vomiting. When the remedy has passed out of the stomach, then the ingestion of fluids may, and ought to be encouraged.

To Sir Francis Milman the profession is highly indebted for hints concerning the importance of accompanying the exhibition of Diuretics with plentiful dilution,^[269] the arguments he adduces elucidate in a very satisfactory manner the view which has been just taken of the Influence of Solubility.

The influence of solubility^[270] in increasing the virulence of a poisonous substance, has already been illustrated very fully (page 135,) and it has also been shewn under what circumstance it may be admissible. When these active substances are administered as remedies, in small doses, the precept respecting their solubility is even more important, for in such cases the smallness of the quantity places their operation more immediately under the control of various incidental agents; destroy the solubility of a medicine, and you will probably divest it of those properties which render it useful. Nitrate of Silver, by coming in contact with a Muriatic Salt, is rendered quite inert, and may be discovered unaltered in the fæces of persons to whom it has been administered. See Argenti Nitras.

Under the article Plumbi Acetas the practitioner will also find that the 176conjunction of this substance with any sulphuric salt, at once deprives it of its valuable properties as a remedy in Hæmopthysis.

Some practitioners, whose opinions I always receive with respect, have considered these views respecting the influence of solubility as savouring too much of the refinement of theory, and instances have been suggested which would appear to invalidate their pretensions; upon examination, however, it will be found that such exceptions are but apparent, and depend upon the solvent action of the gastric fluid. Thus the Protoxide of Iron would appear to be soluble in the fluids of the stomach, and is consequently an active medicine, whereas the Peroxide of the same metal, being insoluble under such circumstances, requires to be combined with an acid, as in the Tinctura Ferri Muriatis, to render it efficacious. The same remark will probably apply to the oxides of antimony.

I shall conclude this section upon the influence of Solubility, by the relation of an anecdote which may tend to confirm the justness of the views I have offered, more satisfactorily perhaps than any additional arguments derived from a scientific examination of chemical and medicinal facts; in as much as it presents us with a practice, the utility of which has been discovered by unassisted experience, and must consequently be independent of theory. The American Indians, whenever they undertake a long journey, and are likely to be destitute of provisions, employ Tobacco for the purpose of counteracting the uneasy sensations of hunger, and in its preparation for such a purpose they adopt an expedient for modifying its powers, and protracting its effects, which affords an instructive illustration of the influence of solubility; it consists in combining the juice of Tobacco, with the pulverized shells of snails, cockles, and oysters;^[271] the mass is dried, and formed into pills, of a convenient size to be held between the gum and lip, which being gradually dissolved and swallowed, fulfil the intention required.^[272]

V.
TO AFFORD AN ELIGIBLE FORM.

A. By which the efficacy of the remedy is enhanced.

After the views which have been submitted in the progress of the present inquiry, it is evident, that the form in which a remedy is administered may exert some influence upon its medicinal effects; for additional proofs of this fact, and for more particular directions, see Decocta, Infusa, Tincturæ, Misturæ, Pilulæ, Pulveres, &c.

When a substance, or a combination of substances, requires the addition of some other one, for the purpose of imparting a convenient, agreeable, or efficacious form, a vehicle should always be selected, whose effects will be likely 177to correspond with the intention of the other ingredients. This precept may be exemplified by a reference to Form. 80, 134, and others, the key-letters of which announce the modus operandi of their respective vehicles.

B. By which its aspect or flavour is rendered more agreeable.

It should ever be the object of the practitioner to accommodate, as far as he is able, the form and flavour of his medicines to the taste and caprice of his patient, provided always that he does not compromise their efficacy, and which often appears to be nearly connected with those sensible qualities which render them disgusting and objectionable.

Some medicines are more grateful to the stomach, as well as more efficacious in their operation, when exhibited in the state of effervescence. To effect this we have only to introduce an alkaline carbonate into the formula, and to direct a portion of some vegetable acid to be added just before it is swallowed. We must, however, take care that the ingredients are of a nature not likely to be decomposed by the alkali, in the first instance, or by the neutral salt, which is formed, in the second. See Form. 27, 82, 86.

C. By which it is PRESERVED from the spontaneous decomposition to which it is liable.

It is sometimes adviseable to add an ingredient for the purpose of preventing the sudden decomposition of a medicine; thus is the Compound Tincture of Cardamoms added to the Compound Decoction of Aloes, in order that the latter may be preserved a longer period without change. The addition of sugar will prevent ointments from becoming rancid. Vegetable infusions, that are susceptible of mouldiness, are best preserved from such deterioration by some aromatic addition. For the knowledge of this fact we are indebted to Dr. Mac Culloch, who in a very interesting paper, lately published in the Edinburgh Philosophical Journal^[273] has observed, that perfumes, such as Essential Oils, &c. will prevent the production and growth of those minute cryptogamous vegetables, upon which the phenomenon of mouldiness depends.^[274]

178Such are the objects which are to be attained by combining several substances in one Formula, and such the laws by which these compositions are to be regulated; but unless a physician can satisfactorily trace the operation of each element in his prescription to the accomplishment of one or more of the objects which I have enumerated, SIMPLICITY should be regarded by him as the greatest desideratum. I was once told by a practitioner in the country that the quantity, or rather complexity of the medicines which he gave his patients, for there never was any deficiency in the former, was always increased in a ratio with the obscurity of their cases; “if,” said he, “I fire a great profusion of shot, it is very extraordinary if some do not hit the mark.” Sir Gilbert Blane^[275] has given us a similar anecdote; “a practitioner being asked by his patient why he put so many ingredients into his prescription, is said to have answered more facetiously than philosophically, in order that the disease may take which it likes best.” A patient in the hands of such a practitioner has not a much better chance than the Chinese Mandarin who, upon being attacked with any disorder, calls in twelve or more physicians, and swallows in one mixture all the potions which each separately prescribes!

Let not the young practitioner however be so deceived; he should remember that unless he be well acquainted with the mutual actions which bodies exert upon each other, and upon the living system, it may be laid down as an axiom, that in proportion as he complicates a medicine, he does but multiply the chances of its failure. Superflua nunquam non nocent: let him cherish this maxim in his remembrance, and in forming compounds, always discard from them every element which has not its mode of action clearly defined, and as thoroughly understood.

The perfection of a Medicinal Prescription may be defined by three words; it should be Precise (in its directions,) Concise (in its construction,) Decisive (in its operation.) It should carry upon its very face an air of energy and decision, and speak intelligibly the indications which it is to fulfil. It may be laid down as a position which is not in much danger of being controverted, that where the intention of a medicinal compound is obscure, its operation will be imbecile.

A Medicinal Formula has been divided into four constituent parts, a division which will be found to admit of useful application to practice, in as much as it was evidently suggested with a view of accomplishing the more prominent objects which have been related in the preceding pages; or, in the language of Asclepiades, of enabling the Basis to operate “Cito,” “Tuto,” et “Jucunde.” Quickly, Safely, and Pleasantly—thus

I. The Basis, or Principal Medicine.

II. The Adjuvans; that which assists and promotes its operation.

III. The Corrigens; that which corrects its operation.

179IV. The Constituens; that which imparts an agreeable form.

These elements however are not all necessarily present in every scientific formula, for many medicines do not require any addition to promote their operation, and the mild and tractable nature of others renders the addition of any corrective unnecessary; whilst many again are in themselves sufficiently manageable, and do not therefore require the intermede of any vehicle or constituent. It also frequently occurs that one element is capable of fulfilling two or more of the objects required; the Adjuvans for instance, may at the same time act as the Corrigens, or Constituens; thus the addition of Soap to Aloes, or Extract of Jalap, mitigates their acrimony, and at the same time quickens their operation (80.) So again Neutral Salts both quicken and correct the griping which attends the operation of resinous purgatives. The disposition of the key letters placed opposite to the elements of the following Formulæ, will furnish the practitioner with a farther elucidation of these principles, viz. 70, 71, 76, 77, 101, 102, 105, 135, &c. This coincidence, if possible, should be always attained, for it simplifies the formula, and by decreasing the bulk of the remedy, renders it less nauseous and more elegant.^[276]

This division also affords the best general rule for placing the ingredients of a formula in proper order, for the order should correspond with that of the arrangement; and those elements intended to act in unity should be marshalled together. The chemical and mechanical nature however of a medicinal substance will occasionally offer exceptions to any general rule; thus the volatile ingredients should be those last added, and the constituent or vehicle should be placed next the particular element to which it is intended to impart convenience or efficacy of form, or a capability of mixing with the other ingredients, as may be seen in Formulæ 69, 71, 127, 136, &c. This consideration induced the Committee, appointed to revise the late Pharmacopœia, to alter the order of the ingredients in the “Mistura Ferri composita,” and to place the “Spiritus Myristicæ” next in succession to the “Potassæ Sub-carbonas” and Myrrh. If any substance require decoction or infusion, a question then arises, determinable only by a knowledge of its chemical composition, whether the remaining ingredients should be added previous to, during, or subsequent to, that operation; Formula 40, which is recommended by Pringle as a remedy for Typhus fever, may serve to exemplify this principle. The preparation of the ingredients is resolved into three distinct stages, and it is easy to discover that by any other arrangement their several virtues could not be fully obtained, and secured from change. The Cinchona, for instance, yields its full powers only by decoction, a process which would necessarily impair those of Serpentaria, connected as they are with an essential oil; whilst the addition of the acid at any other stage of the process 180than that directed, would produce decompositions in the vegetable substances; and it is evident that were the Spirit of Cinnamon added previously, it would be entirely lost by vaporization. So in making the Compound Decoction of Sarsaparilla, the Sassafras should be added after the other ingredients have undergone boiling. The Decoctions of Lichen Islandicus and Sarsaparilla constitute a popular remedy on the Continent, in certain forms of Phthisis; now it is evident that as the former plant loses its virtues by long coction, and the latter requires a protracted ebullition for the extraction of its virtues, they ought not to be included under the same general directions; each decoction should be separately performed, and the results subsequently mixed.

Compound Medicines have been divided into two Classes, viz.

I. Officinal Preparations,

which are those ordered in the Pharmacopœias, and kept ready prepared in the shops. No uniform class of medicines however can answer the indications of every case, and hence the necessity of

II. Magistral or Extemporaneous Formulæ.

These are constructed by the practitioner at the moment, and may be either arrangements altogether new, or officinal preparations with additions, or modifications. Too much importance cannot be assigned to the Art which thus enables the physician to adopt and graduate a powerful remedy to each particular case by a prompt and accurate prescription; without this knowledge, the practitioner of the nineteenth century, with all the collateral aid of modern science, will be as helpless in the chamber of sickness as the physicians of ancient Egypt, who were obliged by the laws to follow with servile exactness the unvarying mandates of their medical code. Extemporaneous are also preferable to Officinal Formulæ, whenever the powers of the compound are less liable to deterioration from being long kept; for examples, see Mistura Ferri composita; Infusum Sennæ; Liquor Hydrargyri Oxymuriatis, &c.

The Chemical and Pharmaceutical Errors, which may be committed in the composition of Extemporaneous Formulæ, are referable to the following Sources.

1.—Substances are added together which are incapable of mixing, or, of forming Compounds of uniform and suitable consistence.

This may be termed an error in the Mechanism of the Prescription, and has been generally regarded as being more inconvenient than dangerous, more fatal to the credit of the Prescriber than to the case of the Patient: the observations however which are offered in this work, especially under the article Pilulæ, must satisfy the practitioner that this error is more mischievous in its effects than has been usually supposed; it is so palpable and self-evident in its nature, that it will be unnecessary to illustrate it by more than one or two examples. Calomel, for instance, has been ordered in an aqueous vehicle, and certain resinous tinctures have been directed 181in draughts, without the necessary intervention of mucilage; so again, an intermixture of substances has been formerly ordered in powder that possess the perverse property of becoming liquid by triture (see Pulveres), and bodies have been prescribed in the form of pills, whose consistence^[277] renders it impossible that they should preserve the globular form; or else they have been so hard and insoluble, that they might be fired through a deal board.^[278] In the London Pharmacopœia of 1809, an error of this kind unfortunately passed without correction with regard to the Formula for preparing the Syrup of Senna.

II.—Substances are added together which mutually decompose each other, whence their original virtues are changed, or destroyed.

This is a more serious, but not a less frequent source of error; it has been already shewn in this Analysis (IV. B) that the judicious and scientific application of chemical science has furnished new and endless resources to the physician, by exalting the efficacy and correcting the acrimony of established remedies, or by combining inert substances so as to create new and powerful medicines. With equal truth and confidence it may be asserted, that the abuse of these means not only destroys the virtues of the most valuable articles in the Materia Medica, but that the mildest remedy may be thus converted into an instrument of torture, and even of death. In a lecture delivered at Apothecaries’ Hall, Mr. Brande stated that he had seen a prescription in which the blue, or mercurial pill, was ordered in conjunction with nitric acid, and that the patient was brought to “death’s door” from the formation of nitrate of mercury in his stomach! I have myself lately seen a Recipe, professing to afford a preparation similar to the “Black Drop,” and which directed a mixture of a Tincture of Opium, made with rectified spirit, with Nitric Acid; in this case, it may be very safely inferred that the author was not only ignorant of the chemical habitudes of these bodies, but that he never performed the experiment in question, or he would have learnt from dire experience, that in consequence of the rapid evolution of nitric ether, the contents of the phial will explode with violence, to the imminent hazard of the operator’s eye-sight. During the course of my professional practice I have witnessed more than an ordinary share of consumptive cases, and I can confidently state that in the treatment of Hæmopthysis, the styptic properties of Acetate of lead are entirely invalidated by combination with Alum,^[279] or by its exhibition being accompanied with that of the acidulated infusion of roses, or with small 182doses of sulphate of magnesia; and yet, I would ask, whether this practice is not usual and general? The practitioner however cannot be too often reminded that he is not to reject a remedy whose value has been ascertained by experience, merely because it appears to be unchemical: the popular and certainly useful pill, consisting of calomel, rhubarb and soap, may be adduced as an example of this kind. Of the Mistura Ferri Composita, I will only say that it is a most valuable combination; and whether it be the product of accident, or the result of philosophical induction, it equally deserves a distinguished place in our list of tonic remedies: but it cannot be denied that many of our esteemed arrangements, which are in apparent contradiction to all the laws of composition, owe their efficacy to the operation of affinities altogether blind and fortuitous.

It has been observed that the practice of combining certain vegetable tonics with lime-water, although very common, is in cases where we are desirous to obtain their astringent effects, of very doubtful propriety; for the fact is, that Tannin forms with the alkalies and alkaline earths, compounds that are not soluble in water,^[280] and which are therefore probably inefficacious. It may perhaps be said that such an argument cannot avail, because if the astringent matter be even introduced into the stomach in its purest form, it will immediately form an insoluble compound on its contact with gelatine.^[281] We know so little of the laws of gastric chemistry, that it is difficult to learn what changes take place in the animal laboratory; but it would seem probable that the powers of the stomach rather consist in decomposing the ingesta into simple forms, than in complicating them by favoring new combinations; besides which, if such a compound were formed, it would be subsequently decomposed in transitu; for the experiments of Sir H. Davy shew that vegetable astringent matter passes through the body unchanged. (page 82.)

It is impossible to furnish any general rule that may enable the practitioner to avoid mixing together substances which are incompatible with each other; a knowledge of their chemical habitudes must in every case direct him, and these are enumerated in the second part of this work, under the history of each medicinal substance. The physician however will find it useful to retain in his remembrance the simple and beautiful law which has been so ably developed by the eminent author of the “Statique Chimique,” that whenever two salts in a state of solution are brought together, which contain, within themselves, elements capable of producing a soluble and insoluble salt, a decomposition must necessarily arise;^[282] he illustrates this law by the example of Nitrate of Silver and Muriate of Potass, whose elements are capable of forming within themselves a soluble 183salt, Nitrate of Potass, and an insoluble salt, Muriate of Silver. It deserves also to be remembered, that a table of chemical affinity will not upon all occasions prove to the medical practitioner an unerring pilot; in those cases for instance, where a super or sub Salt is readily formed, a substance less weakly attracted by another than a third, will sometimes precipitate this third from its combination with the second, thus in the production of Nitric acid, we decompose the Nitrate of Potass by virtue of the superior affinity of the Sulphuric acid for its base, the nitric acid is accordingly disengaged, and a Sulphate of Potass remains in the retort; now, paradoxical as it may appear, if nitric acid be poured upon the Sulphate of Potass, a quantity of nitre will be reproduced, in consequence of the saturation of a portion of the base, in such a proportion as to enable the remaining atoms to form a Bi-Sulphate of Potass. In the same manner the Tartrate of Potass (Soluble Tartar) is, contrary to the usual affinities, decomposed by all sub-acid vegetables, which neutralize a portion of the base, and convert the salt into the Bi-tartrate of Potass (Cream of Tartar). The same effect is even produced by Carbonic acid.^[283]

There are besides certain cases wherein Triple Salts are produced, which afford apparent exceptions to the usual affinities of the bodies involved in the combination; we have a very good illustration of this truth in the decomposition of the Liquor Ammoniæ Acetatis by Magnesia; if the practitioner refers to a table of affinities, he will perceive that Acetic acid has a greater attraction for Ammonia than for Magnesia; but if upon this assurance he were to administer these bodies together, he, or his patient, would soon discover that ammonia is developed with considerable pungency; now in this case the Magnesia forms a triple Acetate with one part of the ammonia, and consequently sets the remainder at liberty.

A popular error exists with respect to the subject of chemical incompatibility, against which it may be here advisable to caution the inexperienced prescriber, viz. that no important change is produced, on the admixture of solutions, unless precipitation is occasioned. This however occurs only when the new compound produced is insoluble; thus Sulphuric acid may be added to Lime water, by which a Sulphate of Lime is formed, but as its proportion is not too large for the water to dissolve, no precipitate occurs; so again, a solution of Nitrate of Silver is not apparently disturbed by the addition of Ammonia, because the resulting Ammoniuret is a soluble compound. We should, nevertheless, commit a great error in supposing that, for such a reason, these bodies were not incompatible. On the other hand, the medicinal powers of a solution are not necessarily destroyed by the occurrence of a precipitate, although such a result should always be regarded with suspicion.

III.—The Methods directed for the preparation of the Ingredients are either inadequate to the accomplishment of the object, or they change and destroy the efficacy of the Substances.

The observations already offered upon Formula 40, will sufficiently explain 184the nature of the various errors comprehended under this head: so, again, if the virtues of a plant reside in essential oils, which are easily volatilized, or in extractive matter, which readily becomes oxidized, Decoction must necessarily destroy its efficacy; a striking example of this fact is presented us in the history of the Laurel and Bitter Almond: the poisonous influence of the essential oil and distilled water of these vegetable substances is well known, but their watery extracts are perfectly innocuous. A still more familiar example is to be found in the onion, or in garlic, which by simple coction is deprived of all its acrimonious qualities. On the other hand, an error equally injurious would be committed, by directing a simple infusion of a vegetable, whose medicinal properties depended upon resino-mucilaginous principles. Orfila found that an extract of Hemlock, prepared by boiling the dried powder in water and evaporating the decoction, was entirely destitute of activity. See Decocta, Infusa, Extracta.

An instance of the baneful effects which may arise from an erroneous method of preparation happened some time ago to fall under my immediate notice and care; it was in preparing an infusion of the root of the Veratrum with Opium, as directed by Mr. James Moore, when the dispenser ignorantly substituted a spirituous for a vinous menstruum.

A very common error may be here noticed, which is that of prescribing a substance in such a form, as not to be acted upon with any effect by the solvent; as an example it may be stated, that in preparing an infusion of Juniper Berries, unless pains be taken by strong contusion to break the seed, it will contain but little power as a medicine.

The unbruised seeds of Mustard were commended by Dr. Mead,^[284] in Ascites, and by Bergius, in Intermittents; Dr. Cullen, however, has very properly observed that the seeds given in the above manner are never broken down or dissolved in the stomach, but pass away entire by stool, and cannot therefore occasion any beneficial result.

It is unnecessary to multiply examples in proof of the numerous errors into which a physician must unavoidably fall, who presumes to compose prescriptions without a knowledge of the chemical habitudes of the different substances which he combines. The file of every apothecary would furnish a volume of instances, where the ingredients of the prescription are fighting together in the dark, or at least are so adverse to each other, as to constitute a most incongruous and chaotic mass.

The Doses of Medicinal Substances are specific with respect to each, and can therefore be only learnt from experience; the young and eager practitioner, however, is too often betrayed into the error of supposing that the powers of a remedy always increase in an equal ratio with its dose, whereas The dose alone very often determines its specific action. “Medicines,” says Linnæus, “differ from poisons, not in their nature, 185but in their dose,” which is but a paraphrase of the well known aphorism of Pliny, “Ubi virus, ibi virtus.”^[285]—So that food, remedies, and poisons, may be said to branch into each other by indefinable gradations;—Five grains of Camphor act as a mild sedative and slight diaphoretic, but twenty grains induce nausea, and act as a stimulant; so again, Opium, in too large doses, instead of promoting, prevents sleep, and rather stimulates the bowels than acts as a narcotic. Two ounces of any neutral salt are apt to be emetic, one ounce even of Alum to be cathartic, and two drachms to be refrigerant; in like manner the preparations of Antimony either vomit, purge, or sweat, according to the quantity exhibited.

Would it not appear that powerful doses rather produce a local than a general effect? Experience seems to prove in this respect, that the effect of an internal application is similar to that of an external impression; if violent, it affects the part only to which it is applied, as pinching does that of the skin, whereas titillation, which may be said to differ only from the former in degree, acts upon the whole system, and occasions itching and laughter, and if long continued, weakness, sickness, vomiting, and convulsions; in like manner Digitalis, if given in large doses, acts immediately upon the stomach or bowels, becoming emetic and cathartic, but in smaller proportions it produces a General effect, increasing all the excretions, especially that of urine; so, again, large doses of the Mercurial Pill act upon the bowels, and are eliminated from the body, whereas the same remedy in small doses affects the system generally, and excites a universal influence. I am well satisfied that the regulation of the dose of a medicine is even more important than it is usually supposed to be. Substances perfectly inert and useless in one dose may prove in another active and valuable. Hence may be explained the great efficacy of many mineral waters, whilst the ingredients which impart activity to them are found comparatively inert, when they become the elements of an artificial combination; and hence probably the failure of many alterative medicines, when no other rational cause can be assigned for it. We need not seek far for an example of the very different and opposite effects which the same substance can produce in different doses; the operation of Common Salt is familiar to us all; Sir John Pringle has shewn that in quantities such as we usually take with our food, its action is highly septic, softening and resolving all meat to which it is applied, whereas in large quantities it usually preserves such substances from putrefaction, and therefore, when so taken, instead of promoting, destroys digestion.

186It is moreover probable that medicinal, like nutritive substances, are more readily absorbed into the circulating system when presented in small quantities, than when applied in more considerable proportions. It is upon this principle that a large quantity of food, taken seldom, does not fatten so much as smaller quantities at shorter intervals, as is exemplified in the universal good condition of cooks and their attendants. It is not pressing the principle of analogy too far to suppose that the action of alteratives, which require to be absorbed, may be more effectually answered by similar management; that is, by exhibiting small doses at short intervals.

The operation of medicines is influenced by certain general circumstances, which should be also kept in mind when we apportion their dose; e.g. Age—Sex—Temperament—Strength of the Patient—Habit—Diet—Profession—Climate—Duration of the Disease—State of the Stomach—Idiosyncrasy—and The variable Activity of the Medicinal Substance.

Women generally require smaller doses than men. Habit, or the protracted use of a medicine, generally diminishes its power, although certain cathartics appear to offer an exception, for when long continued, their activity is proportionally increased, as is well known to every person who is familiar with the operation of the Cheltenham waters. Dr. Lamb has also stated with regard to the operation of Lead, “that the constitution, so far from being reconciled to it by habit, is rendered more and more sensible to its irritation by continuance.” Emetics also frequently become more powerful by repetition; Cullen informs us that he knew a person so accustomed to excite vomiting in himself that the one twentieth part of a grain of tartarized antimony was sufficient to excite a convulsive action of the stomach; in some cases such an effect may perhaps be referred to the operation of the mind; for after the frequent use of an emetic, the mere sight of it, or even conversation relative to it, has been found sufficient to excite nausea.

In apportioning the dose of a very active medicine, it is of the greatest moment to determine the relative degrees of power between the system and the remedy, and to know to what extent the latter is likely to be carried, consonantly with the powers of life to resist it; thus, after a patient has been exhausted by protracted and severe suffering and watching, a dose, different to one at the commencement of the disease is requisite. The importance of this precept is impressed upon my mind from having witnessed, in the course of my practice, several instances of the mischief which has arisen from a want of attention to it; that disease materially influences the condition of the body, and its susceptibility to remedial impressions, has been already demonstrated. Emetics act very readily in febrile affections, while in those of the Neuroses^[286] they produce their effects with difficulty.

In the application of external remedies to diseased parts, it especially behoves the Surgeon to take into consideration the degree of vitality possessed by such parts, and to graduate their strength accordingly.

Mr. Henry Earle^[287] has published a very interesting case in illustration of this principle. The arm of a person became paralytic, in consequence 187of an injury of the axillary plexus of nerves from a fracture of the collar bone; upon keeping the limb for nearly half an hour in a tub of warm grains, ‘which were previously ascertained by the other hand not to be too hot,’ the whole hand became blistered in a most alarming manner, and sloughs formed at the extremities of the fingers, and underneath the nails; a considerable degree of inflammation subsequently spread in the course of the absorbents, and matter formed in the axilla, which was soon absorbed, and the inflammation assuaged. Whence it follows, that a limb deprived of its usual supply of nervous energy cannot sustain, without injury, an elevation of temperature which would not be in the least prejudicial to a healthy member. Mr. Earle supports this conclusion by the relation of another case, in which the ulnar nerve had been divided, for the cure of a painful affection of the arm; the consequence of which operation was, that the patient was incapable of washing in water at a temperature that was quite harmless to every duly vitalized part, without suffering from vesication and sloughs.

Before we quit the subject of Dose, it may be necessary to observe, that there are many remedies that do not act with greater violence in a large dose than in one comparatively small; Ipecacuan, for instance, is more certain in its operation, but not more violent, when given in a large quantity; the same may be said of Aloes, and several other medicines.

The Variable Activity of a Medicine should also be appreciated, and perhaps the practitioner would act cautiously if he were to reduce the dose, should it be a very considerable one, whenever a fresh parcel of the medicine is commenced, especially of the powders of active vegetables liable to deterioration from being kept, as those of Digitalis, &c.

The Time of the Day at which remedies should be administered deserves likewise some attention. Evacuating Medicines ought to be exhibited late at night or early in the morning. It would seem that during sleep the bowels are not so irritable, and consequently not so easily acted upon, which allows time for the full solution of the substance; the same observation applies to Alterative and other medicines which are liable to suffer from a vexatious irritability of the bowels; it is on this account eligible to exhibit Guaiacum, Pilulæ Hydrargyri, &c. when they are not intended to purge, at bed time. On the other hand, where the effects of a remedy are likely to be lost by perspiration, as is the case with Diuretics, many of which are by external heat changed into Diaphoretics, it may become a question with the judicious practitioner whether he cannot select some more favourable period for their exhibition.

In fevers it is of importance to consult in all respects the quiet and comfort of the patient; Dr. Hamilton therefore, in his valuable work on Purgatives, very judiciously observes that, on this account, the exhibition of purgative medicines should be so timed, that their effects may be expected during the day.

In some cases the time of administering a remedy must be regulated by the stage of the disease; thus, in fevers, a dose of opium will either increase the heat of the body, augment thirst and restlessness, or occasion tranquillity and sleep, according to the temperature of the body at the time of its administration; for this reason Dr. Currie advises us not to give the evening dose of Opium in Typhoid fevers, till very late, or about one or two o’clock in the morning, when the heat is subsiding, and moisture is coming on. Emetics administered for the cure of the slighter 188cases of Pyrexia should be given in the evening, as their operation leaves a tendency to sleep and diaphoresis, which it is useful to promote. Remedies that require to be absorbed will probably be more efficient in the morning after sleep; the old custom of giving medicines on a morning fasting, is not quite so absurd as some modern practitioners have been led to suppose. Diaphoretics should be always given after the digestive process is ended, for during the performance of this function the emunctories of the skin are less disposed to action.

The Intervals between each Dose must be regulated by the nature of the remedy and that of the objects which it is intended to fulfil, and whether it be desirable or not that the latter dose should support the effects of the preceding one, or whether there be any fear of a reaction or collapse taking place after the effect of one dose has subsided, unless immediately repeated; thus the effects of diffusible stimulants, such as ammonia and æther, are very evanescent, they should therefore be repeated at short intervals; the same may be said of Diaphoretics, especially the lenient ones; we ought not to allow the period between the doses to be so remote as to occasion any striking abatement in the impression: so Opium, where its primary and stimulant operation is required, as in diseases of debility, such as fevers of the typhoid type, should be given in small doses at short intervals, so that it may enkindle and sustain a uniform and regular state of excitement: but where the object is to mitigate pain, allay irritation, and produce sleep, it ought to be exhibited in full doses, at distant intervals. There is a caution also which it is very necessary to impress upon the practitioner, respecting the power which some medicines possess of accumulating^[288] in the system; this is notorious with regard to Lead and Mercury, and probably with the preparations of Arsenic, and some other metallic compounds. Dr. Withering has observed that the repetition of small doses of Digitalis, at short intervals, till it produces a sensible effect, is an unsafe practice, since a dangerous accumulation will frequently take place before any signals of forbearance present themselves. I have already alluded to the possibility of mercurial accumulation, and its developement at a remote period.

Constitutional Peculiarities, or Idiosyncrasies, will sometimes render the operation of the mildest medicine poisonous, “Virum novi,” says Gaubius, “qui cum fatuum lapidum cancrorum pulvisculum ingessit, vix mitius afficitur quam alii ab Arsenico.” I have seen a general Erysipelas follow the application of a blister, and tormina of the bowels, no less severe than those produced by the ingestion of Arsenic, attend the operation of purgatives composed of Senna! In some constitutions Antimony has been known to produce a ptyalism; Dr. James assured Sir George Baker that he knew six instances of it, although the patients thus affected had neither their teeth loosened, nor their breath made offensive. The peculiar susceptibility of certain individuals to the effects of particular plants is also 189very singular: Murray relates that unpleasant symptoms have been experienced by merely keeping Aconite for some time in the hand, or on the bosom. I am acquainted with two persons in whom the odour of Ipecacuan always produces a most distressing dyspnæa; Mr. Chevalier informs us, that he once knew a lady who could not take Powdered Rhubarb, without an erysipelatous efflorescence almost immediately shewing itself on the skin, and yet she could take it in the form of Infusion with perfect impunity. There are some idiosyncrasies so singular and incredible, that nothing but unimpeachable testimony could sanction our belief in their existence. Schenkius relates a case in which the general law of astringents and cathartics was always reversed. Donatus tells us of a boy whose jaws swelled, whose face broke out in spots, and whose lips frothed, whenever he eat an egg.

The late Pope Pius VII. had such an antipathy to musk, that on one occasion of presentation, an individual of the company having been scented with that perfume, his holiness was obliged to dismiss the party almost immediately.^[289] Education, and early habits certainly establish very extraordinary peculiarities in different countries with respect to various objects of diet and luxury: what shall we say of the refinement of the Ancients who regarded the flavour of the Citron with disgust, while the odour of putrid fish was deemed by them so exquisite, that they carried it about in caskets of onyx as a favourite perfume! Custom makes the Greenlander relish his train oil; and Dr. Heberden tells us, that there is a town in North America, where the spring-water is brackish, and that, when the inhabitants visit any other province, they choose to put salt into their tea or punch, in order, as they say, “to make it taste as it should do.”^[290]

Climate. Several observations have already been offered upon the influence of Climate in affecting the activity of our remedies.^[291] With regard to its relations to Dose, I have only one remark to make to the English practitioner, and that by the way of caution, that he will not allow his own previous experience in hot climates, or the persuasions of other tropical practitioners to induce him to administer such doses of Mercury, in England, as may have been found salutary in India, or in other Colonies of similar temperature.

The popular scheme of Gaubius for graduating the doses of medicine to different ages, which was published in several of the former editions of this work, is now omitted, as being less easy of application than the following simple formula by Dr. Young.

RULE.

For children under twelve years, the doses of most Medicines must be diminished in the proportion of the Age, to the Age increased by 12.

Every general rule however respecting the doses of medicines will 190have exceptions. Thus children will bear larger doses of Calomel than even adults, and many medicines which do not affect adults, although exhibited in considerable quantities, prove injurious even in small doses to children.^[292]

In concluding this part of the subject, it is proper to impress upon the practitioner the importance of writing his prescriptions in legible characters, and of avoiding all those abbreviations which are not generally understood, or which are capable of misconstruction.^[293]

SOLID FORMS.

PULVERES. Powders.

The form of powder is in many cases the most efficient and eligible mode in which a medicinal substance can be exhibited, more especially under the following circumstances.

1. Simple Powders.

1. Whenever a remedy requires the combination of all, or most of its principles, to ensure its full effects, as Bark, Ipecacuan, Jalap, &c.

2. Where medicinal bodies are insoluble, and indisposed to undergo those essential changes, in transitu, which render them operative; for it must be remembered that by minute division, every particle is presented to the stomach in a state of activity, being more immediately exposed to the solvent or decomposing powers of that organ.

3. Where the mechanical condition of the substance is such as to occasion irritation^[294] of the stomach, as the Sulphuretum Antimonii, or in external applications to produce an improper effect upon the skin, as Hydrargyri nitrico-oxydum.

191The degree of fineness to which substances should be reduced by pulverization, in order to obtain their utmost efficacy, is a very important question. The impalpable form appears to be extremely injurious to some bodies, as to cinchona, rhubarb, guaiacum, and to certain aromatics, in consequence, probably, of an essential part of their substance being dissipated, or chemically changed by the operation. Fabbroni, for instance, found by experiment that cinchona yielded a much larger proportion of soluble extractive, when only coarsely powdered. I think it may be laid down as a general rule, that extreme pulverization assists the operation of all substances whose active principles are not easily soluble, and of compound powders whose ingredients require, for their activity, an intermixture; whilst it certainly injures, if it does not destroy, the virtues of such as contain as their active constituent, a volatile principle which is easily dissipated, or extractive matter which is readily oxidized.

2. Compound Powders.

The disintegration of a substance is much accelerated and extended by the addition of other materials; hence the pharmaceutical aphorism of Gaubius, “Celerior atque facilior succedat composita, quam simplex pulverisatio.” Thus several refractory vegetable bodies, as myrrh, gamboge, &c. are easily reduced by triturating them with sugar or a hard gum; and some gum resins, as assafœtida or scammony, by the addition of a few drops of almond oil. Upon the same principle the Pharmacopœia directs the trituration of aloes with clean white sand, in the process for preparing Vinum Aloes, to facilitate the pulverization and to prevent the particles of aloes, when moistened by the liquid, from running together into masses; some dispensers very judiciously adopt the same mechanical expedient in making a tincture of myrrh; so again, in ordering a watery infusion of opium, it will be judicious to advise the previous trituration of the opium with some hard and insoluble substance, as directed in the Pulvis Cornu Usti cum Opio, otherwise its particles will adhere with tenacity, and the water be accordingly unable to exert a solvent operation upon its substance.^[295] It is equally evident that in the construction of compound medicinal powders, the addition of an inert ingredient, which the mere chemist might condemn and discard as useless, not unfrequently acts a very important part in the combination, owing to its effects in dividing and comminuting the mere active constituents: the sulphate of potass in Dover’s powder acts merely in dividing and mixing more intimately the particles of opium and ipecacuan: the phosphate of lime appears to act in the same mechanical manner in the Antimonial Powder; so again, in the Pulvis Contrajervæ compositus, the prepared oyster shells may be a necessary ingredient: in the Pulvis Jalapæ compositus of the Edinburgh College, the cream of tartar greatly increases the activity of the jalap, by 192breaking down its substance and dividing its particles; and Van Swieten observes that the operation of this resinous purgative is improved by bruising it with sugar, and adding some aromatic. The old combination of Pulvis Helvetii consisted of alum and dragon’s blood, and there can be no doubt but that the effect of this latter ingredient, which has been often ridiculed, was to retard the solution of alum in the stomach, in consequence of which the preparation was likely to produce less inconvenience, and could therefore be administered in larger doses; the Edinburgh college has substituted gum Kino in their Pulvis Aluminis compositus, which may have the same effect in modifying the solubility of the alum.

In rubbing together different substances, it is necessary to remember that there are many saline bodies, which in the dry state become moist and even liquid, by triture with each other, and that, under such circumstances, they are susceptible of mutual decomposition. This change is effected by the action of water, derived from the following sources.

1. From the water of crystallization. This always operates when the proportion contained in the original ingredients is greater than that which the products can dispose of; that is to say, whenever the capacity of the new compound for water is less than that of the original ingredients. By previously driving off this water by heat, we shall of course avoid such a source of solution, and no liquefaction can ensue. Thus, if recently burnt quick-lime be triturated with calomel, the resulting mixture will be white, shewing that no decomposition can have arisen, but add a few drops of water, and it instantly assumes a dark aspect. If crystallized sulphate of copper be triturated with Acetate of lead, the resulting mixture will assume a fine green colour, but if the sulphate of copper be previously heated, and its water of crystallization driven off, no change of colour will be produced; if, for Acetate of lead, we substitute muriate of lime, and the sulphate of copper be crystallized, we shall obtain a result of a yellow colour, but if the sulphate of copper be anhydrous, the product will be colourless, becoming however instantly yellow, like the former, on the addition of a drop of water; and on a further addition of this fluid, the yellow product in both instances will be rendered blue; which proves that a chemical decomposition has taken place, and a muriate of copper resulted; for this salt is rendered yellow by a small, and blue by a larger proportion of water. The Cuprum Ammoniatum presents another illustration, for the ingredients, when rubbed together, become extremely moist, and undergo a chemical decomposition. Certain resinous bodies also, as myrrh, become liquid by triture with alkaline salts, in which case the resin and alkali form a soluble compound, which the water of crystallization, thus set at liberty, instantly dissolves.

2. From aqueous vapour in the atmosphere. The water of the atmosphere does not act upon these occasions, unless it be first attracted and absorbed by one of the triturated bodies; e. g. if Acetate of lead and recently burnt alum be triturated together, no change will be produced; but, if the burnt alum be previously exposed for a short time to the atmosphere, these bodies will, in that case, become liquid.

The physician, without this chemical knowledge, will be often betrayed into the most ridiculous blunders, an instance of which very lately came to my knowledge in a prescription for the relief of cardialgia and constipation, in the case of dyspepsia; it directed sulphate of soda and carbonate of potass, in the form of a powder, but the fiat of the physician, upon this occasion, 193only served to excite the ridicule of the dispenser, who soon discovered that the ingredients in his mortar dissolved into liquid.

During the exhibition of powders containing insoluble matter, it is always important to maintain a regularity in the alvine excretions, or an accumulation may take place attended with very distressing symptoms. Dr. Fothergill relates a case of this kind which succeeded the use of powdered bark; and Mr. E. Brande has communicated a similar instance of mechanical obstruction, produced by the habitual use of magnesia. I could also add, if it were necessary, some striking facts of a similar tendency, which occurred from eating bread that had been adulterated with pulverized felspar. The precaution seems more particularly necessary in the case of children, whose bowels are very impatient of extraneous and insoluble contents.^[296] The dose of a powder ought not to exceed ʒj; and, when taken, should be diffused in water, wine, or any other convenient liquid; resinous and metallic powders require a thick and consistent vehicle, as syrup or honey, since they subside from those which are more fluid.

PILULÆ. Pills.

These are masses of a consistence sufficient to preserve the globular form, and yet not so hard as to be of too difficult solution in the stomach. The subject offers some extremely interesting points of inquiry. The following general rules will enable the practitioner to select those substances to which the form of pill is adapted, and to reject those to which it is not suitable, as well as to direct, extemporaneously, the most efficient mode of preparation.

I. The Selection of Substances.

1. Suitable Substances are, 1, All remedies which operate in small doses, as Metallic Salts; and 2, Those which are designed to act slowly and gradually, as certain Alterative Medicines, or 3, which are too easily soluble when exhibited in other forms, as Gamboge, &c. 4, Substances which are not intended to act until they reach the larger intestines, as in pills for habitual costiveness; see Aloes. 5, Bodies whose specific gravities are too considerable to allow their suspension in aqueous vehicles. Efflorescent salts may also be exhibited in this form, but they ought to be first deprived of their water of crystallization, or the pills composed of them will crumble into powder as they dry.

2. Unsuitable Substances are, 1, Those which operate only in large doses. 2, Which deliquesce. 3, Whose consistence is such as to require a very large proportion of dry powders to afford them a suitable tenacity, as oils, balsams, &c. 4, Substances that are so extremely insoluble, that when exhibited in a solid form they pass through the canal unaltered, as certain extracts.

194Many remedies which are incompatible with each other in solution, may be combined in pills, unless indeed their medicinal powers are adverse or inconsistent, or their divellent affinities sufficiently powerful to overcome their state of aggregation.

II. Their Formation into Masses.

This is a subject of far greater importance than is usually assigned to it, as will be more fully explained in the sequel.

1. Many substances, as vegetable extracts, may be formed into pills without any addition; others, as gum resins, become sufficiently soft by being beaten, or by the addition of a drop or two of spirit, or liquor potassæ. Some dry substances react upon each other, and produce, without the addition of any foreign matter, soft and appropriate masses. The Pilulæ Ferri Compositæ, of our Pharmacopœia afford a very striking example of this peculiar change of consistence, which the mutual reaction of the ingredients produces by simple triture. The Pilulæ Aloes Compositæ offer another instance; for the extract of gentian, upon being triturated with aloes, produces a very soft mass, so that the addition of a syrup, as directed by the Pharmacopœia, is quite unnecessary. See Form: 12.

2. Many substances are, in themselves, so untractable, that the addition of some matter foreign to the active ingredients, is absolutely essential for imparting convenience of form. It is generally considered that very little skill and judgment is required in the selection of such a substance, provided it can fulfil the mechanical intention just alluded to—the fact however is, that the medicinal power of the pill may be materially controlled, modified, or even subverted, by the mode in which it is formed into a mass. Where the active element of a pill is likely to be improved by minute division, a gummy or resinous constituent may be usefully selected: under the history of Aloes, I have alluded to a popular pill, known by the name of the dinner-pill, in which case the mastiche divides the particles of the aloes, and modifies the solubility of the mass. The Pilulæ Opii of the former Pharmacopœia of London, consisted of equal proportions of opium and extract of liquorice, and the mass was so insoluble that its effects were extremely uncertain and precarious; in the present edition, soap has been very judiciously substituted; but in certain cases where we wish to protract the influence of opium, or that of any other active body, so as not to obtain its full effects at once, we may very advantageously modify its solubility by combining it with a gum resin or some substance which will have the effect of retarding its solution in the stomach. The Pilulæ Styrace of the Dublin college, presents itself as an efficient example of this species of pharmaceutical address; see also Form. 10, 11, 12. I am well acquainted with many formulæ whose utility has been sanctioned by experience, and I have no hesitation in believing that their salutary mode of operation would receive a plausible explanation from this simple law of combination. Dr. Young has very justly stated in his Medical Literature,^[297] that the balsam of copaiba envelopes metallic salts, so as to lessen their activity; he says that the sub-carbonate of iron, made into pills with copaiba, was given for some weeks without any apparent effect; and 195that a few hours after the same quantity had been given, with gum only, the fæces were perfectly black. I do not know a more striking and instructive proof of the influence of a glutinous or viscid constituent, in wrapping up a metallic salt, and defending the stomach from its action, than is presented in the case published by the medical attendant Mr. Marshall, in consequence of the attempt of Eliz. Fenning to poison the family of Mr. Turner of Chancery-lane by arsenic, which she providentially administered in a heavy yeast dumpling. Soap is very frequently used for the formation of pill-masses, and it is an excellent constituent for substances likely to be injured by meeting with an acid in the primæ viæ; many resinous bodies may also be reduced to a proper consistence by soap, although in prescribing it, its levity should be attended to, or otherwise the pills will be too bulky; in general it will combine with an equal portion of any resinous powder, as Rhubarb, Jalap, &c.; it is of course ineligible where the substances are decomposed by alkalies, as Tartarized Antimony; this last precaution will also apply to aromatic confection as a vehicle, on account of the carbonate of lime contained in it. The Conserve of Roses has the advantage of retaining its consistency much longer than mucilage, but as it contains an uncombined acid, it is frequently inadmissible; it could not for instance be with propriety employed with the precipitated sulphuret of antimony. Pills made with mucilage, are apt to crumble when they are rolled out; this is the case with the Pilulæ Hydrargyri submuriatis; some extract therefore would be a more convenient constituent; in this particular case, however, the addition of a few drops of spirit would supersede the necessity of any constituent. Castor oil, in some cases, especially with some of the harder purgative extracts, will impart an eligible consistence.

Crumb of bread, furnishes a convenient vehicle for those salts which are ponderous, active in very small doses, or which are liable to be decomposed by other vehicles; but an objection is attached even to this, for it is liable to become so dry and hard when kept, that pills made with it will frequently pass undissolved. Swediaur mentions this fact with reference to Plenck’s mercurial pill, as well as to one of corrosive sublimate, and he proposes for this reason to substitute starch; the addition however of a small portion of sugar will prevent the bread from becoming thus indurated, and with such a precaution it may be very safely employed. For the purpose of forming active vegetable powders into pills, such as Digitalis, Conium, &c., I am informed by Mr. Hume of Long Acre, that in his experience melasses or treacle is the best constituent that can be selected, for it undergoes no decomposition by time, but maintains a proper consistency, and preserves the sensible qualities of the plant quite unimpaired for many years. I have deposited in the cabinet of the College, specimens of such pills, of hemlock and foxglove, which retain the characteristic odour of these vegetables, notwithstanding they have been now made for several years. Honey has likewise the property of preserving vegetable substances; seeds may be kept in it for any length of time, some of which, on being taken out, washed, and planted, will even vegetate. It has also been used for the preservation of animal matter; the bodies of the Spartan kings, who fell at a distance in battle, were thus preserved, in order that they might be carried home.^[298]

196Water will on some occasions be found a convenient expedient; powdered Rhubarb or Jalap may be thus made into masses without any increase of bulk, but the pills will be apt, if kept, to become mouldy.

3. In the formation of pills the ingredients should be hastily rubbed together, whenever they are liable to be injured by long exposure to the air; thus in the formation of Pilulæ Hydrargyri submuriatis compositæ, the compound is rendered less active by too long continued triture. See Pulveres.

4. In dividing pill-masses, it is usual to add to them, and envelope them in, magnesia; where calomel is present, I have satisfied myself by experiment that a muriate of magnesia is formed under such circumstances, and it is owing to this partial decomposition, that the surface of the pill exhibits a greenish hue; starch, powder of liquorice,^[299] or orrice root, might perhaps under such circumstances be more judiciously preferred. In Germany, the powder of Lycopodium is generally used. Formerly, the pill was covered with gold leaf, which protected it from the influence of the stomach, and frequently rendered it unavailing.

It has been observed that many of the pill-masses directed in our Pharmacopœias, are liable to become so hard^[300] and dry by being kept, that they are unfit for that division for which they were originally intended; indeed Dr. Powel considers it doubtful whether the greater number of articles had not better be kept in powder, and their application to the formation of pills left to extemporaneous direction; the necessity of this is farther apparent, when we learn that it is a common practice for the dispenser to soften these masses by the application of a hot spatula, or pestle, which sometimes carbonizes, and frequently decomposes them.

III. Their Form of Prescription.

In our extemporaneous directions, it is necessary to apportion with accuracy the quantity of active materials which we may wish each pill to contain, and since the proportion of the constituent can rarely be exactly defined, the equable division of the whole mass, into a given number of pills, will be safer than defining the weight of each pill.

A pill, the bulk of whose ingredient is vegetable matter, ought not to exceed five grains in weight, but where the substances which compose it are metallic and ponderous, it may without inconvenience weigh six or even eight grains.

As these are regarded as objects rather of confectionary than of pharmacy, the London and Dublin Colleges have not condescended to notice them; the Edinburgh Pharmacopœia, however, contains several formulæ for their preparation; and as the form of lozenge offers a very commodious and efficacious method of administering certain remedies, the theory of its operation deserves some notice in the present work. It is principally useful in cases where it is an object that the remedy should pass gradually into the stomach, in order to act as powerfully as possible upon the pharynx and top of the trachea, as in certain demulcents or astringents; for instance, Nitre, when intended to operate in relaxed or inflamed states of the tonsils, is best applied in this manner; so is Sulphate of Zinc in chronic coughs, attended with inordinate secretion. In order to retard as long as possible the solution of the lozenge in the mouth, it ought to be composed of several demulcent substances, such as farinaceous matter, sugar, gum, and isinglass; for such a mixture will be found to answer the purpose better than any one of these articles taken by itself; thus the farinaceous matter will prevent the sugar and the gum from being too soon dissolved; the viscidity of the sugar and gum will prevent the farinaceous matter from being swallowed as soon as it would otherwise be; and the isinglass will give a softness to the whole, and thus prevent any sharp points from stimulating the membrane.

SUPPOSITORIA. Suppositories.

This form of preparation is very ancient, and although it has of late years fallen into disuse, it affords an efficacious mode of administering many powerful remedies, and in some instances of producing effects which the same medicine would not command if given in any other form: besides which, it is found that after the stomach by long use has lost its susceptibility to the action of medicine, such a substance will operate with fresh and unabated force if applied to the rectum. There are two great indications which Suppositories are calculated to fulfil, viz.

1, The alleviation of pain and irritation, especially when it arises from diseases of the bladder, prostate gland, uterus, and other parts in the vicinity. Abortion may be thus frequently prevented. To fulfil these intentions, a mixture of opium with two parts of soap, will be found eligible. I can recommend such an application from a well grounded experience in its efficacy.

2, The production of Catharsis. In cases of Apoplexy, from the counter-irritation which these remedies are likely to occasion, much advantage may arise; and in the failure of more common measures, they may be applied with certain success in the cure of Ascarides; see Formula 146. Where a very efficient Suppository is required, one or two grains of Elaterium rubbed up with eight grains of hard soap, will present us with a combination of great utility.

This is an ancient form of prescription; for although the term “Electarium” is first used by Cælius Aurelianus, yet the ἐκλὶκτον of Hippocrates, and the Antidotus, Confectio, Mithridatium, Diascordium, Opiatum, Orvietanum, Philonium, Theriaca, and Requies of other authors, were all Electuaries. They differ from Conserves in this, that the sugar in the latter preparations is in a greater proportion, and is intended to preserve the ingredients; whereas in the former, it is merely intended to impart convenience of form; see Confectiones. Electuaries are in general, extemporaneous preparations, composed of dry powders, formed into a proper consistence by the addition of syrup, honey, or mucilage; when however the latter substance is employed, the electuary very soon becomes dry and hard: and when common syrup is used, the compound is apt to candy, and in a day or two to grow too hard for use; this is owing to the crystallization of the sugar; Deyeux therefore states, that the syrup should be previously exposed to the heat of a stove so long as it forms any crystals, and that the residual liquor, which from the presence of some vegetable acid has no tendency to crystallize, may then be advantageously applied;—Melasses or Treacle may in some cases be employed, and from experiments which I have repeated with some care, I am enabled to state that the peculiar flavour of this liquid is entirely removed by a simple operation, which consists in diluting it with an equal weight of water, and then boiling it with about one eighth part of powdered charcoal for half an hour, when the liquor is to be strained, and reduced by gentle evaporation to a proper consistence;^[301] and moreover it appears, that active vegetable powders retain their characteristic qualities when immersed in treacle, longer than in any other excipient.

In selecting and prescribing this form of exhibition, the following general rules should be observed.

I. Those substances which are nauseous, deliquescent, which require to be given in large doses, or which are incapable of forming an intimate union with syrup, as fixed oils, balsams, &c. should never be prescribed in the form of an electuary.

II. The quantity of syrup directed must be regulated by the nature and specific gravities of the substances which enter into their composition, viz.

1. Dry Vegetable Powders require twice their weight of syrup, or of honey.

2. Gummy and Resinous Powders require an equal weight.

3. Hard Mineral Substances should be formed into an electuary with some conserve, as they are too ponderous to remain suspended in syrup. It deserves also to be noticed, that in consequence of the readiness with which metallic preparations undergo change, it will be generally adviseable to keep the active ingredients in the form of powder, and to add them to the syrup only just before they 199are required; the Electuary of the French Pharmacopœia, which is commonly called “Opiata Mesenterica,” will furnish a good example, “quantumvis molle fuerit recens, progressu temporis, ob ferrum quod ipsi inest, mirè indurescit.”

LIQUID FORMS.

MISTURÆ. Mixtures.

These preparations are generally extemporaneous, in which different ingredients are mingled together in the liquid form, or, in which solid substances are diffused through liquid, by the medium of mucilage or syrup: for prescribing mixtures the following general rules may be laid down.

I. Substances which are capable of entering into chemical combination, or of decomposing each other, ought not to be mixed together, unless it be with a view of obtaining the new products as a remedy.

II. Transparency is not a necessary condition,^[302] and hence insoluble powders may be advantageously introduced into mixtures, if the following precautions be observed.

1. They must be divisible and mechanically miscible in the liquid.

2. They must not possess too great a specific gravity.

3. They must not render the liquid too mucilaginous or thick; thus, f℥j should seldom contain more than ʒss of a vegetable powder, ℈ij of an electuary, and conserve; or grs. xv, or ℈j of an extract.

III. The taste, the smell, and the general aspect of the mixture should be rendered as pleasant as possible; thus milk covers the taste of bark, of the tinctures of guaiacum and valerian, and that of lime water; and a light decoction of the liquorice root disguises a bitter taste more effectually than sugar.

The Physician may also produce occasional changes in the appearance of his mixture, in order to reconcile a delicate taste to its continuance; he never ought however to alter the essential part of plans which he finds advantageous.

A Draught differs merely from a mixture in quantity; it is usually taken at once, and should not exceed f℥iss; it should be always preferred when,

1. The remedy is to be taken in a precise dose.

2. Whenever it is liable to spontaneous decomposition.

3. Whenever the action of the atmosphere occasions change.

In apportioning the dose of mixtures, the following proportions are admissible, although not perfectly accurate. A Table Spoon full (Cochleare Amplum) f℥ss. Dessert Spoon (Cochleare Mediocre) more than fʒij. Tea Spoon (Cochleare Minimum) fʒj. A Wine Glass (Cyathus) 200although very variable, may be estimated as containing f℥iss. The custom of measuring the dose of a liquid by dropping it from the mouth of a phial is very erroneous;^[303] it will therefore be proper to dilute an active medicine that is to be so apportioned, with at least a triple quantity of water, that its real dose may not be essentially altered by any slight variation in the quantity.

The temperature at which a liquid medicine should be given may perhaps merit a few observations. In general, the ordinary degree of heat is that which will best answer the intention, but in cases of dyspepsia, the sense of weight and uneasiness, which often follows a dose of medicine, will be prevented by giving it in a tepid state. This remark will apply to the administration of the Decoction of Sarsaparilla; Refrigerants should of course be given as cool as possible; Camomile Infusion, and other vegetable Ptisans, which are designed to promote the operation of an emetic, will be more efficient when warm. In delicate chlorotic females I have sometimes found chalybeate draughts not only more efficacious, but less distressing to the stomach, when exhibited in a tepid state.

ENEMATA. Clysters.^[304]

This form of applying a medicine furnishes the practitioner with many valuable resources, although the remedy has not escaped its due share of persecution. Paracelsus bestowed upon it the epithet “turpissimum medicamentum,” and Van Helmont that of “pudendum medicorum subsidium.”

It is calculated to fulfil the following indications, viz.

1. To promote the tardy operation of a Cathartic, or to evacuate the bowels, where, from delicacy of stomach, medicines cannot be retained, or from debility of body they cannot be safely administered.

In the administration of a remedy of this kind, there are two essential circumstances, independent of the strength of its ingredients, which will modify its activity, viz. Impulse and Quantity, by which we obtain the stimulus of distention; warm water without any adjunct may thus be made the means of overcoming those unrelenting obstructions, which had refused obedience to more common measures: Clysters, however, when most forcibly urged, rarely reach beyond the sigmoid flexure of the colon, and yet when the largest quantity of fluid which the bowels will admit is introduced with considerable impulse, the local impression is so powerful that it is at once extended by the medium of sympathy, through the whole of the alimentary canal, and very thorough and copious discharges result.

2. To induce extreme relaxation:

Which is best effected by an infusion of Tobacco. See Tabaci Folia.

3. To produce Astringent and Anodyne, or Carminative effects.

Common starch, with the addition of Tincture of Opium, is the most common and convenient form for this purpose. See also Assafœtida, Terebinthinæ Oleum, and Formulæ 8, 9, 29, 30. In some cases the injection 201of cold water acts as a powerful astringent, and from its impression upon the rectum, will frequently afford instantaneous relief in the piles.

4. To destroy Ascarides. See Form. 164.

5. To act as an emollient fomentation.

6. To convey nutriment.

In the administration of Clysters, for the fulfilment of any of the last five indications, it is obvious, that the stimulus of distention should be avoided, as being incompatible with our object; the quantity, or bulk of the solution, ought to be also carefully graduated; to prevent, for example, the opiate clyster from being too soon returned, Dr. Cullen has remarked that it seldom should be made of more bulk than that of three or four ounces of liquid, and this also of a very mild kind. In administering a bitter decoction for the cure of Ascarides, the same precaution is necessary, or the gut will suddenly contract and expel the clyster, which always acts with more certainty when allowed to remain for some time. The proportions of fluid vehicle necessary for the different stages of life, under ordinary circumstances, may be stated as follows:—An infant at its birth, or soon after, requires about one fluid ounce; a child between the age of one and five years, from three to four fluid ounces; a youth of ten or fifteen, from six to eight fluid ounces; and an adult may take twelve. With regard to the dose of the active ingredient of a Lavement, it may be estimated as triple of that taken by the mouth.

INJECTIONES.

Under this head may be comprehended the various medicinal preparations which are employed as local applications;—to the urethra for the cure of gonorrhæa, and to the vagina for that of the different discharges to which females are liable.

With respect to the former of these it has been truly observed, that “among the whole class of remedies employed for surgical purposes, there is scarcely one which has occasioned a greater diversity of opinion;” to enter however into an examination of this subject would be entirely foreign to the intention of the present work; it is only necessary to state, that for their preparation the same principles of combination, and the same chemical precautions, apply, as have been already investigated under the head Misturæ. In some cases the practitioner will find it useful to insure the entire solution of his active ingredient; while in others, the presence of a precipitate may enhance the efficacy of the application, as illustrated by Form. 62.

In the preparation of injections for the cure of female discharges, it must be remembered that, if they be of a vegetable nature, their efficacy wholly depends upon the Tannin which they contain, and the prescriber must therefore take care not to invalidate the force of this principle by any incompatible additions.

And it deserves to be remembered, that as Tannin has the power of coagulating animal mucus, and of forming with it an insoluble precipitate, its administration, as an injection, is liable to occasion the evacuation of whitish or ash-coloured flakes, which will come away from time to time, and excite in the patient’s mind, says Mr. Clarke, the apprehension that she is voiding portions of the internal parts of the body, unless her mind be prepared for the occurrence by a previous explanation, and which the 202judicious practitioner will not neglect to afford. In some cases it will be necessary to correct the irritating effect of the astringent by the addition of a demulcent, as exemplified in Form. 61. In applying this form of remedy an ivory syringe should be always preferred to one of pewter, whenever the solution is likely to be affected by the contact of a metal.

INHALATIONES. Inhalations.

Under this general title may be comprehended two distinct classes of volatilized substances, viz.

Dry Fumes (Suffitus), and Watery Vapours (Halitus).

Before we enter upon the consideration of this particular form of remedy, it may be necessary to state, generally, that it appears to be capable of affording a very expeditious and powerful mode of affecting the body by certain medicines. If the power of a remedy be so greatly modified by circumstances affecting its solubility, as we have already proved, it cannot be a matter of surprise that the still farther diminution of its cohesion should occasion a corresponding influence upon its energies; indeed it would appear that some few substances are entirely inert when applied under any other form, see Hydrargyrum, in the after part of this work. We are, moreover enabled by these means, to bring various bodies into immediate contact with organs, which are inaccessible to such remedies in every other state of aggregation. This observation applies more particularly to the lungs, and the subject has lately occupied the attention of a worthy and skilful physician, whose work^[305] is well entitled to the serious consideration of the profession.

The practice of causing patients to inhale various volatilized substances appears to have been of very ancient date. It has been already stated in this work (p. 39) that the fumes of Orpiment were directed to be breathed by Galen, and that the practice has been adopted by practitioners of later date.^[306] Few attempts of this kind however were made, until the time of our countryman Bennet, the author of “Theatrum Tabidorum,” who arranges volatilized substances into the two classes which have been announced at the head of the present section, viz. Suffitus, and Halitus. The numerous trials which have been since made with the different gases must be in the remembrance of every reader, but unfortunately, the injudicious and empirical spirit with which these inquiries have hitherto been conducted, has thrown such discredit upon the subject, that the practitioner who should resume the investigation, must be prepared to hear his understanding, or his integrity, questioned.

Suffitus. Fumes of Burning Substances. The particular forms of pulmonary disease in which Tar fumes appear to be most serviceable, are of the chronic kind; where an inflammatory diathesis prevails, or any tendency to hæmopthysis exists, the practice cannot be said to be free from 203danger. In treatment of hooping cough the inhalation of tar fumes have been also said to be beneficial. For the mode of applying this remedy, see Pix Liquida.

The practice of smoking the roots of Stramonium, Tobacco, &c. might with propriety be noticed under this head. With the respect to the former of these remedies, much has been said and written, and asthmatic patients have occasionally expressed a belief in its palliative powers; in my own practice however, I have never met with any success that has inspired my confidence. See Stramonii Herba.

Halitus. Aqueous Vapours. In certain catarrhal affections, when accompanied with painful and difficult expectoration, benefit may be occasionally obtained from the inhalation of the steam of hot water, or of vinegar and water, the acid in this case assisting the expectoration, while the whole acts as an emollient and soothing application to the tender and inflamed vessels of the internal surface of the bronchial tubes. The same practice is also highly serviceable in Cynanche Trachealis, and Tonsillaris.

In Pneumonia, after the violence of the arterial excitement has been reduced by depletory measures, the inhalation of the steam of hot water, or decoctions of emollient herbs, will often contribute to the support of an easy expectoration.

It has been already stated under the history of Expectorants (page 106), that in certain dry states of the air, the evaporation of water in an artificially warmed apartment, is frequently attended with considerable relief to the pulmonary patient.

In Dyspnæa, attended with a spasmodic condition of the pulmonary organs, vapours impregnated with sulphuric æther have been recommended for inhalation. Dr. Pearson also states that the efficacy of such an application is materially enhanced by dissolving in it a portion of the extract of Conium. Dr. Bôotcher of Copenhagen, has lately announced the utility of vapours of camphor, in complaints affecting the cavities of the nose, throat, and chest. He states that in the worst case of stoppage of the nose from catarrh, a piece of camphor need only be kept for a few minutes before it, to obtain great relief; the same application has been known to produce good in Cynanche Tonsillaris.

In order to apply such inhalations we may employ the inhaler invented by Dr. Mudge, or if that instrument be not at hand, the spout of a tea pot, or a common basin with an inverted funnel, will be found very convenient substitutes.

REMEDIES OF EXTERNAL APPLICATION.

This class of medicinal agents formerly comprised a much wider range of forms than it at present contains; such as numerous Epithems; Vapours; Aromatic Bags; Medicated Quilts, &c.

The external remedies of the present day may be divided into two orders, viz.

1. Those whose effects are entirely local, as exemplified in the application of certain refrigerating embrocations, stimulating cataplasms, and astringent unguents.

2042. Those which excite general effects, or produce an influence upon parts remote from those to which the remedy is more immediately addressed, as illustrated by the operation of mercurial liniments and unguents, or by the general tonic effects of adhesive plaisters.

With respect to the former of these divisions it is unnecessary to multiply our remarks; the objects which they embrace belong more particularly to the department of surgery, and from the investigation of the different modes and forms of external application we shall hereafter derive very ample and instructive illustrations. In considering the objects of the latter division, a very interesting and important question immediately suggests itself for our consideration—How far a medicinal substance, when locally applied to the surface of the body, may be capable of affecting the general system, or some of its more remote parts?—the experienced practitioner will feel no hesitation in admitting numerous proofs of the existence of such agency; and it would seem probable that topical applications may produce general effects by several distinct modes of operation, viz.

1. By exciting an impression on the nervous system.

2. By modifying the cuticular discharge.

3. By being absorbed into the circulation.

In considering the different forms of external applications, it will appear that, for their extemporaneous construction, preparation, and application, the same scientific knowledge, practical skill, and pathological acumen will be required, as we have already stated to be so indispensably requisite to enable the physician to prescribe, and the pharmaceutist to prepare the various remedies intended for internal administration; although in regard to the former, it may be stated generally that the prescriber will more frequently be called upon to exercise that species of knowledge and address which enables the practitioner to impart a convenient and efficient consistency to his remedy; for an external application is far more dependent upon this circumstance for its efficacy, than one intended for internal use.

LOTIONES:

Remedies of a liquid nature, designed for external application.

Under this generic term, which strictly signifies a wash, may be comprehended several species of medicines, calculated for the fulfilment of different indications, as Embrocationes, Collyria, Fomenta, Linimenta, &c. In some instances these applications are entirely local in their effects, as where a morbid action of the skin is changed by a stimulating lotion, as exemplified in the cure of Psora by the decoction of Hellebore, or the relaxed vessels of the tunica conjunctiva of the eye, by an astringent collyrium; in other cases, they operate upon parts not in contact with the remedy, through the medium of sympathetic communication, as where cholic and disorders of the bowels are abated by the application of warm fomentations to the surface of the abdomen, or where paralytic affections are relieved by pumping cold water on the part affected.

Embrocationes. These, as the term^[307] denotes, are compositions of 205spirit, decoctions, infusions, or other liquids, applied by sprinkling or rubbing them on an affected part.

Linimenta^[308] are understood to differ from embrocations in consistence, the former being of an oily, or mucilaginous density, which increases their efficacy by imparting a certain emollient power, in addition to their other virtues. In popular language, however, liniment and embrocation are generally considered synonymous terms. They constitute a valuable class of remedies, and the observations which Dr. Percival has offered on their utility well merit the attention of the medical practitioner. “Volatile and antispasmodic liniments are highly useful remedies, and it is to be lamented that external applications of this kind are not more frequently employed, for there is just reason to apprehend that powerful effects might be expected from them in various diseases.” In chronic affections of the viscera, such applications appear highly serviceable, not only from the friction to which they give origin, but from the influence of that species of sympathy which appears to depend upon the mere proximity and continuity of parts, and which, as Sir Gilbert Blane has observed, is particularly displayed “in the containing on the contained parts, as that of the integuments on the subjacent viscera.”

Collyria^[309].—Liquid applications to the eyes. The Pharmacopœia Chirurgica contains several different formulæ for lotions of this kind, some of which are simply astringent, while others combine also the virtues of a stimulant.

CATAPLASMATA.^[310] Poultices, or Pultices.

External applications of a pulpy, and somewhat coherent or tenacious consistence.

They are generally extemporaneous preparations, and are calculated to answer several different indications, viz.

1. As Stimulants, e. g. Cataplasma Sinapis, L. D. which generally inflames the surface to which it is applied so much as to raise blisters; common salt also, muriate of soda, constitutes the active ingredient of a poultice which has lately been brought into considerable repute for the reduction of indolent strumous swellings and enlargements of the glands.^[311]

2. Antiseptics—Cataplasma Fermenti, L. (see p. 159.) A powerfully antiseptic cataplasm may be also made by stirring finely powdered charcoal into a common linseed meal poultice. A cataplasm of the boiled carrot, beat into a pulp, has been likewise found very effectual in sweetening foul ulcers.

3. Sedatives. The most efficient of these are composed of Conium, Digitalis, or Hyoscyamus, and are eminently serviceable in cancerous and scrophulous sores of a highly irritable and painful nature, 206to diminish their sensibility and correct the acrid discharges. See Form. 18.

4. Refrigerants. In the formation of a cataplasm for this purpose we must avoid the introduction of substances that are slow conductors of caloric; suppose for example our object is to apply the sub-acetate of lead in this form, it will in such case be judicious to mix the linseed meal, with oatmeal, or crumb of bread; for if the former substance be used singly, it is liable, from its tenacity, to become hard and dry, and in that state to augment the temperature which it was designed to diminish.

5. Emollients.—(The modus operandi of these agents is explained at p. 142.) For which purpose the common farinaceous poultice is the most eligible, made by soaking slices of bread in milk, and simmering them together over a gentle fire until they are reduced to the proper consistence, which ought to be such as to prevent its spreading farther than is designed, and yet not so hard as to occasion any mechanical irritation; the whole is then to be beat smooth with a spoon, and applied as warm as the patient’s feelings will readily admit. Some practitioners have doubted the propriety of milk as an ingredient in this composition, and have preferred water as an excipient, not only because the former is very liable to turn sour, but because it does not possess greater powers as an emollient than water; the observations of the editor of the Pharmacopœia Chirurgica upon this question are judicious, and worthy our notice; “the objection,” he says, “will certainly hold good whenever stale milk is made use of, or if the same poultice be kept too long applied; but if the milk be fresh, and the poultice renewed night and morning, we do not know any thing that occasionally gives such ease and comfort to the patient as this form of cataplasm. If water be substituted for milk, the poultice is seldom of sufficient tenacity; it is true that this inconvenience may be remedied by the addition of a little linseed meal, but in some instances the meal appears to fret and irritate the skin so much, that patients undergo considerable uneasiness from this cause; an objection to which the cataplasm of bread and milk is seldom subject, especially if it be not applied too hot.”

Every substance, whether liquid or solid, may become an ingredient in this species of composition, and although judicious and experienced surgeons have of late very considerably improved the form of their cataplasms, yet the principles of medicinal combination, which it has been the object of the present work to investigate and expound, will suggest many important hints for the farther extension of their utility; and although the direction of them is more frequently left to the nurse than to the medical practitioner, yet in adapting them to each particular occasion some share of chemical address may be necessary; we have already seen that attention must be paid to the selection of ingredients, with respect to their powers of conducting heat, and it is evident that care must be taken not to reduce into pulp, by decoction, substances that contain volatile principles; while in the preparation of active liquids to be subsequently mixed with linseed meal, it is equally evident 207that we must be directed by the chemical nature of their composition.

EMPLASTRA. L.E.D. Plasters.

These are solid and tenacious compounds, adhesive at the ordinary heat of the human body; they owe their consistence to different causes, viz.

1. To a due admixture of wax or fatty matter, and resin, e. g. Emplast: Ceræ, &c.

They may be said to differ only in consistence from liniments, ointments, and cerates; Deyeux^[312] accordingly proposes to distinguish them by the appellation of Solid Ointments.

2. To the chemical combination of the semivitreous oxide of lead with oils or fat, e. g. Emplast: Plumbi.

3. To the chemical action of the component parts of the plaster on each other, as Emplast: Ammoniaci, &c.

Plasters are generally kept in rolls, wrapped in paper, and when to be used they are melted and spread on leather; in performing this operation the practitioner ought not to apply a heat above that of boiling water; for if metallic oxides be present, the fatty matter will, at a higher temperature, reduce them, in consequence of the powerful affinity of oil for oxygen at an exalted temperature; and if aromatic substances enter as ingredients they will thus suffer in their strength, besides which the fat itself will undergo a very injurious change by a mismanaged application of heat, and the plaster will be less adhesive.

They are employed as remedies to answer two general indications; mechanically, to afford support to muscular parts and to prevent the access of air; and medicinally, to operate as stimulants, discutients, rubefacients, or anodyne applications. That by affording an artificial support to the various parts of the body, by the application of plasters, we are capable in certain diseases of effecting much benefit, is a truth to be explained upon the principles of physiology, and is daily confirmed by the results of practice; thus by giving support to the muscles of the back, how frequently the stomach is steadied and strengthened? Diseases of the kidneys are in the same way very frequently relieved by tight bandages around the loins; the existence of an intimate connexion between the external and internal parts is strikingly exemplified by the distressing effects which are often experienced in weak habits, such as sickness, giddiness, and other uneasy sensations, from a want of any usual compression, as that of stays, under-waistcoats, &c. The support afforded to persons who have been tapped in Ascites is another instance. I have also lately met with a case in which a morbidly relaxed state of the bowels had harassed the patient for several years, and set at defiance every astringent medicine; upon the application, however, of a tight bandage around the abdomen, the healthy action of the intestines has been completely restored. Sir Gilbert Blane has suggested the trial of mechanical compression of the head in the cure 208of Hydrocephalus, and several cases, apparently favourable, have been published. Dr. Thackrey of Cambridge has related a very interesting history in support of the practice, and judiciously recommends the substitution of straps of adhesive plaster for the bandages of cloth originally proposed by Sir Gilbert. In reasoning upon this treatment, it will be found strictly conformable with the soundest principles of physiology, and with those views in particular, for the illustration of which I have here directed the reader’s attention to the subject. Where our object is simple support, we should of course select a plaster which is the most adhesive and the least irritating. Many plasters which have gained great celebrity for their curative virtues will be found to owe all their powers to their adhesiveness, such is the Emplastrum Oxidi Ferri Rubri of the Edinburgh Pharmacopœia, for it is impossible that the iron should communicate any tonic effect. The same observation applies to many of those empirical plasters which have at different times acquired so great a share^[313] of popular applause. In the cure of sore legs^[314] the importance of adhesive strapping is generally acknowledged, and on such occasions nothing is superior to the Emplastrum Resinæ.

Explanation of the Key Letters.

The Modus Operandi of the different elements of each formula is designated by a Key Letter, or Symbol, which is printed in a different type, (thus B) and placed in the margin opposite to each. This letter refers to a corresponding one in the Synopsis, and thereby shews the division containing an exposition of the principles upon which the operation of the ingredient is supposed to depend.

Two or more Key Letters denote that the element against which they are so placed has several modes of operation, whilst the order in which the letters succeed each other, serves to shew the relative importance of them.

Where any one of the letters is small, i. e. not a capital, it denotes that the operation which it is intended to express is only incidental to, or subordinate in, the general scheme of the combination.

When any number of elements are included within a vinculum or bracket, it is intended to shew that they operate but as one substance, or, that the virtues of each are not independent of the other; in this case the Key Letter within the bracket expresses upon what principle this unity depends, whilst that on the exterior shews the action of such a combination upon the base, or the part which it performs in the general scheme of the Formula.

Let us exemplify it by a reference to Formula 78 which presents us with a Purgative, in conjunction with a Stimulant. The base is Aloes, which is succeeded by Scammony, and Extract of Rhubarb; these substances appear by the bracket, to act in unison, a concurrence which the interior letter B shews to depend upon their being Similar Remedies; the letter also on the exterior shews that its operation upon the base depends upon the same principle. We next come to powdered Capsicum, and Oil of Cloves; these ingredients are also shewn by a bracket to act in unity, and the letter B in the interior, denotes that it is in consequence of their possessing a similar mode of action, whilst the letter G on the exterior, announces that they act in the general scheme for the purpose of fulfilling a second indication; at the same time the smaller letter e informs us that the combination likewise acts as a corrector of the base.^[315]

OBJECT I.
TO PROMOTE THE ACTION OF THE BASIS.

Key Letters.

 

A

A.—By combining the several different forms, or preparations of the same Substance.

B

B.—By combining the Basis with Substances which are of the same Nature, i. e, which are individually capable of producing the same effects, but with less energy than when in combination with each other.

C

C.—By combining the Basis with Substances of a Different Nature, and which do not exert any Chemical influence upon it, but are found by experience, or inferred by analogy, to be capable of rendering the stomach, or system, more susceptible of its action.

OBJECT II.
TO CORRECT THE OPERATION OF THE BASIS, BY OBVIATING ANY UNPLEASANT EFFECTS IT MIGHT BE LIKELY TO OCCASION, AND WHICH WOULD PERVERT ITS INTENDED ACTION, AND DEFEAT THE OBJECT OF ITS EXHIBITION.

D

A.—By CHEMICALLY neutralizing, or MECHANICALLY separating, the offending ingredient.

E

B.—By adding some substance calculated to guard the stomach, or system against its deleterious effects.

OBJECT III.
TO OBTAIN THE JOINT OPERATION OF TWO, OR MORE MEDICINES.

F

A.—By uniting those Medicines which are calculated to produce the SAME ULTIMATE RESULTS, but by modes of operation totally different.

G

B.—By combining Medicines which have entirely different powers, and which are required to obviate different symptoms, or to answer different indications.

OBJECT IV.
TO OBTAIN A NEW AND ACTIVE REMEDY, NOT AFFORDED BY ANY SINGLE SUBSTANCE.

H

A.—By combining Medicines which excite different actions in the stomach and system, in consequence of which NEW, or MODIFIED RESULTS are produced.

 

B.—By combining substances which have the property of acting CHEMICALLY upon each other; the results of which are—

I

  a. The Formation of New Compounds.

K

  b. The Decomposition of the Original Ingredients, and the developement of their more active elements.

 

C.—By combining Substances, between which no other change is induced than a diminution, or increase in the Solubility of the principles in which their Medicinal virtues reside.

L

  a. By the intervention of Substances that act CHEMICALLY.

M

  b. By the addition of Ingredients whose operation is entirely Mechanical.

OBJECT V.
TO AFFORD AN ELIGIBLE FORM.

N

  a. By which the Efficacy of the Remedy is enhanced.

O

  b. By which its Aspect or Flavour is rendered more agreeable, or its mode of administration more convenient.

P

  c. By which it is Preserved from the spontaneous decomposition to which it is liable.