PHARMACOLOGIA; BEING AN EXTENDED ENQUIRY INTO THE OPERATION OF MEDICINAL BODIES, UPON WHICH ARE FOUNDED THE THEORY AND ART OF PRESCRIBING. By J. A. Paris, M.D. Edition Ninth. London: Highley, 1843.

If the number of editions through which a book has passed, be a fair standard whereby to judge of its merits (and certainly a strong plurality, and high desert generally go hand in hand), the book now under consideration comes before the world with powerful recommendations. We shall present our readers with an analysis of the practical parts of it, interspersing our own remarks as we go along, Before, however, we enter on the more immediate subject of which the work treats, we cannot forbear expressing our decided and cordial concurrence in the truth and justice of certain remarks made by the author in the preface to his work. He states, and we think with much propriety, that although the medical public were already in possession of several pharmaceutical compendiums drawn up for the purpose of directing the practice of the junior, and of relieving the occasional embarrassments of the more experienced practitioner, and had books on materia medica, pharmaceutic chemistry, &c. sufficiently descriptive of the natural history, sensible qualities, chemical constitution and medicinal virtues of the several articles used in medicine, as also explaining the various pharmaceutical operations by which such bodies might be rendered available as remedies, still there was something yet wanted; no directions were given to teach the student, when the medicines were put into his hands, how he should mix, combine, and order their application in the form of extemporaneous prescription. It is well known to every experienced practitioner that, amidst all the perplexities which beset the young practitioner, there is none more embarrassing than that of adapting a prescription to all the circumstances of a particular case with therapeutical propriety and chemical accuracy. For the want of such guidance he is necessarily abandoned, on commencing his career of practice, to the alternative of two great evils-a servile routine on the one hand, and a lawless empiricism on the other. In the truth and value of these observations we repeat we entirely concur. We have only to regret that our author has not, in these remarks, pointed out the sources whence the student should derive, in the first instance, this knowledge which was to enable him to prescribe with therapeutical propriety and chemical accuracy; for surely he does not mean to say that his work was to fulfil these very important and essential ends; the former, viz. the prescribing with therapeutical propriety, if we understand the Doctor aright in his use of the terms, can only be obtained from an acquaintance with pathology, that is, in plain English, with the nature, symptoms, signs and seats of disease, as well as with that very particular and important branch of the science, viz. general therapeutics, namely, the various indications of treatment, and the most judicious methods of fulfilling them; such knowledge, combined with a thorough acquaintance with the physiological and therapeutical action of medicines will secure him sufficiently against the danger of therapeutical impropriety; whilst a knowledge of chemistry in general, as well

as of the chemical habitudes and relations of the medicines employed, will keep the practitioner quite clear of the quicksands of chemical inaccuracy. These remarks we have been induced to make from our apprehending that the inexperienced student might be led to suppose that Dr. Paris intended that the study of his work was to supersede the necessity of perusing those works expressly devoted to chemistry, materia medica, and pathology. The author never meant such a thing. The object of his book is to teach the student the best method of applying the knowledge derived from the study of the above sciences, when he is called on to prescribe for the cure or alleviation of disease-and justice obliges us to say that his book will be found to effect this object most completely and satisfactorily. The author apologizes for omitting in the present edition that portion of his work which constituted the materia medica, referring the student to the excellent works of Christison and Pereira for information on that subject. In this we think Dr. Paris acted wisely.

In lieu of this part he offers the compensation of a much more extended view of that province, "which," he says, "I must continue to regard as peculiarly my own, for no author of the best repute has hitherto invaded it—the philosophy of medicinal combination." We have been so long accustomed to associate in our minds great modesty and great merit, that we very much regretted to meet such an assertion coming from Dr. Paris.

We fancy we hear some surly critic ill-naturedly exclaim" exceptio probat regulam," in which exclamation we however do not join. Certainly Dr. Paris must recollect that Gaubius led the way in one of those departments which constitute the subject of his (Dr. P.'s) book in his celebrated work, entitled Ars concinnandi formulas, from which, by the way, modern medical writers are so fond of borrowing without the least acknowledgement; whilst the department treating of the classification, and modus operandi of medicinal substances had been anticipated by the late Dr. Murray. No doubt Dr. Paris has availed himself in the most dexterous, we mean of course the most judicious, manner, of the vast improvements which have been since introduced into the various branches of medical science; but he is in error when he says that the province of pharmacology is peculiarly his own; Gaubius and Murray invaded the province and conquered it; Dr. Paris took peaceable possession of it, and has made vast improvements in it-in a legal sense, however, we must admit that it is his own, possession being, as the saying is, nine points of the law.

PART I. which contains merely the REVOLUTIONARY HISTORY of the Materia Medica, we shall pass over, as not admitting of analysis, and shall proceed at once to

PART II. IN WHICH ARE CONSIDERED THE OPERATIONS OF MEDICINAL SUBSTANCES, AND THE CLASSIFICATIONS FOUNDED ON THEM.

"Medicines are defined to be those bodies which by due administration are capable of producing changes in the condition of the living system, whereby its morbid actions may be removed or controlled." That medi

cines are for the most part but relative agents, producing their effects in reference only to the state of the living frame, is a truth which our author is very anxious to impress on the mind of the young practitioner. He concurs with Sir Gilbert Blane in believing 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. We must say we do not go the entire length with our author; we are inclined to think that the therapeutical effects of medicines (their virtues) should be deducible from their primary or physiological effects, at least there should be some connexion between them.

The particular Organs, Fluids, and Tissues of the Body may be acted on through Four distinct Channels, or Modes of Communication.

I. BY THE ACTUAL CONTACT OF THE APPROPRIATE REMEDY.

A. Conveyed through the medium of the circulation to distant parts, without decomposition.

Internally.

a. Through the lacteal vessels.

b. Through the branches of the venæ portarum.

c. Through the capillaries,

d. Through the absorbents of the alimentary canal.

e. Through the absorbents of the bronchial vessels.

Externally.

f. Through the divided blood-vessels.

g. Through the lymphatics.

B. Conveyed by absorption, with decomposition; by which one or more of its constituents are developed, and carried into the circulation.

a. Through the same channels as in the preceding case.

II. BY AN IMPULSE CONVEYED THROUGH THE INSTRUMENTALITY OF

NERVES.

a. Through the sympathy of their peripheral extremities.

b. Through the intervention of the nervous centres, and their reflex action.

III. BY THE SYMPATHETIC CONTROL EXERTED BY THE STOMACH AND ALIMENTARY CANAL ON DISTANT PARTS.

IV. BY THE OPERATION OF CONTIGUOUS SYMPATHY, OR BY THAT WHICH

IS EXCITED BY THE MERE PROXIMITY OF PARTS.

On each of these several divisions the author makes several remarks.

1. A. On Remedial Agents conveyed by Absorption WITHOUT DECOMPOSITION. "That certain bodies are capable of evading the assimilating functions, and of entering unchanged into the circulation is a fact, capable of physiological, chemical, and therapeutical demonstration; thus, the physiologist has proved that

a substance introduced into a closed cavity may disappear, the chemist has traced it into the blood, and detected its presence in the secretions, or tissues of the body, while the physician has recognised its specific effects upon the organs with which it has come into contact, or through which it has passed. Among the substances which so pass, are the carbonate, chlorate, nitrate, and sulpho-cyanite of potass, and the bi-borate of soda-these pass unchanged through the blood, and are excreted by the kidneys. Ferro-cyanuret of potass (prussiate of potass) has been detected in the urine by Westrumb, from two to ten minutes after it had been swallowed, as well as by several other physiologists after different intervals.

"I have myself made many experiments upon this subject, and have verified to my entire satisfaction several of those of Christison, Coindet, Tiedemann, and others."

On the subject of the absorption of substances from the surface of the body, three distinct propositions are included: 1st. With respect to the absorbing powers of the skin from simple contact: 2d. From friction. 3d. From the removal of the cuticle. On these several questions, we beg leave to refer to the work itself.

A most interesting question has arisen in modern times, as to the mechanism of absorption. It is now very generally believed that there are no vessels terminating by open extremities, as Haller and others imagined; and even Bichat's idea of exhalant vessels being the open side-branches of the capillaries has been disproved. The opinion now prevails that all animal textures are permeable to fluids, by virtue of their pores, and that absorption is effected by what Majendie calls Imbibition; the phenomena of which, under the terms of Exosmose and Endosmose, have been fully investigated by M. Dutrochet.

"The medicinal substance, then, having, through one or more of the channels above stated, found its way into the general current of the circulation, the next enquiry is, as to what becomes of it. Here, then, arises another question of singular interest, and of great practical importance, as being one which will not only influence our theoretical views, but which must give a scientific direction to our practice. It is evident that the substance thus introduced must either be subsequently ejected from the body, through the medium of some of its secretions or excretions or become united to some of its textures-or combined with, or wholly decomposed by, the vital action of the blood or its vessels."

"That certain remedies should act upon particular organs," says our author, " and leave others wholly uninfluenced, is a fact which appears to me to be far less mysterious than some physiologists have supposed. The substance in question necessarily pervades the whole organisation, through the medium of the circulating blood; but it will only affect such organs as possess a peculiar susceptibility of its action."

The author should have seen that the "peculiar susceptibility" extricated him from no difficulty, save that of a petitio principii, or at least a some thing exceedingly like it.

Our author next considers the subject of—

1. B. Remedial Agents conveyed into the System by Absorption, WITH DECOMPOSITION, by which one or more of the constituents are developed. In this category are included the greater number of substances that act by being absorbed; as there are comparatively few that do not undergo

some change during their transit and final exit from the body. It was a maxim of Cullen's, that with respect to vegetables, and also some animal substances, "it is often a certain portion of them only that can be subjected to our digestive organs, while the medicinal part of the same is hardly affected, and therefore it may be alleged that their operation on the interior parts is not prevented by the powers of digestion." Our author lays claim to the merit of having been the first who attempted to give to this vague proposition a more definite form, or to examine the laws by which such decompositions may be governed. Since his having done so, writers on the Materia Medica have accepted the theory, and it now very generally enters into all speculations regarding the operation of medicinal bodies.

Our author adopts the classification of Dr. Murray, with a few additions of his own.

His classification is as follows;-A. General STIMULANTS. B. ConTRA-STIMULANTS. C. LOCAL OR SPECIAL STIMULANTS. D. CHEMICAL REMEDIES. E. MECHANICAL REMEDIES. F. ALTERATIVES. Under each of these six heads he arranges several classes. The first of these heads he sub-divides into a. Diffusible, and b. Permanent. To the Diffusible belong Exhilarants, Narcotics, and Anti-spasmodics, and to the Permanent, Stimulants, Tonics, and Astringents. The physiological correctness of this arrangement has been frequently disputed; it has been found, however, extremely difficult, nay even impossible, to substitute one wholly free from objection. We have often thought, that, if the primary effects of medicinal substances could be made the criterion of classification, much confusion might be avoided; we are well aware, however, that a serious objection could be made here also, as the primary effect itself is variable, depending, as it frequently does, on the quantity administered. The truth of the maxim, that medicines are mere relative agents, appears no where so striking as in the case now before us; let the system be languid and oppressed from intestinal accumulations, the operation of a purgative will, by unloading the bowels, relieve the state of languor and oppression, and so exhibit all the effects of a stimulant; let the brain or the lungs be congested, venesection will, by removing this state, arouse the powers of the system, and so act the part of a stimulant.

The two most essential processes of animal life," says our author, "are nutrition and excretion, and these are exclusively performed by capillary vessels; suppose the balance of their circulation to be disturbed; mercury, by restoring and equalizing it, might, in certain cases, prove a true stimulant." In this small compass there is some physiology which may admit of question. In the first place, we are told that "the two most essential processes of animal life are nutrition and excretion it is usually taught that nutrition and excretion are by no means processes of animal life, but of vegetative or organic life-letting that, however, pass, what means the balance of their circulation being disturbed"? -what precise idea is to be annexed to these words? what can, properly speaking, unequalise the circulation? we know that the circulation may become quicker or slower, stronger or weaker, or more or less irregular, in a part, but it cannot be unequal; the blood must be sent equally to every part of the body, passing as it does from the heart through a single canal-the aorta.