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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.

“Historia quoquo modo scripta delectat.”

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 art, 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 that, 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 surrounding 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 first 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 Caracalla 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] and 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]

“At Phœbi nondum patiens, immanis in antro

Bacchatur Vates, magnum si pectore possit

Excussisse deum: tanto magis ille fatigat

Os rabidum, fera corda domans, fingitque premendo.”

Æneid, l. vi. 78.

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 unseasonable collection of those remedies which are of vegetable origin,—and, the obscurity which has attended the operation of compound medicines.