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 with 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 our 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 in 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.