REVIEW.

RAT'

ART. I.

Observations on the Blood. By WILLIAM STEVENS, M. D., &c. Read at the Royal College of Physicians, May 3d, 1830. London, 8vo.

EXCLUSIVE systems have long since lost their attractions for the great body of enlightened physicians a certain evidence of the improved condition of the profession, and the triumphant result of the great increase, the wide diffusion, and the rapid circulation of knowledge. It is over minds, limited in their acquirements, and inclined, by that very limitation, to exaggerate, and attach undue importance to few and isolated observations, and to embrace with avidity every fanciful speculation which ingenuity can invent, or the love of novelty suggest, that partial hypotheses, and chemical doctrines, exercise the most unbounded influence.

66

Quicquid delirant reges, plectuntur Achivi."

As the resources of the intellect are enlarged, it acquires vigor and comprehensiveness in its operations; and, rejecting all hasty and rash conclusions, embraces in its grasp the greatest possible multiplicity of facts, before it attempts their generalization. By pursuing this cautious method of induction, the cultivators of the physical sciences have made the most wonderful strides towards their perfection; and by a similar course alone, can principles in medicine ever be fixed on à firm and immutable basis. The past history of the art holds out, indeed, little encouragement for favorable anticipations of the future, and seems to lend confirmation to the prevailing opinion, that it will ever continue to be unstable in its doctrines. But is the reasoning founded on this inference altogether just? We conceive not. The circumstances under which medical, like other scientific investigations, have been hitherto pursued, are mate14

VOL. I.

rially changed. The regular and systematic plans, upon which not only the exact sciences, but also those connected with the moral and intellectual faculties, are cultivated, the augmented number of scientific laborers, the more general acquaintance with the just rules of logic-and, finally, the permanency and diffusion, bestowed upon even the most limited exertions of individual industry and speculation, by the press ;-these present an infallible security against the recurrence of those revolutions and vicissitudes, in the state of the profession, which have hitherto rendered it the sport of wit and scepticism.

It is, in our opinion, no slight proof of the progressive career of improvement, which our science is henceforth destined to run, that the attention of the profession is once more seriously directed to inquiries into the state of the fluids in disease.

Coeval with medicine, and identified with it by Hippocrates and Galen, the humoral pathology continued to impress the very form of every successive theory adopted in the schools to explain the mysterious agency of disease on the human body, until Hoffman, Cullen, Brown, Darwin, and Rush, indignantly ejected it altogether from their systems. Nor is the selfstyled physiological reformer more favorably inclined towards this ancient doctrine. Even the profound Pinel, whose philosophical nosography will remain as an enduring monument of accurate clinical observation, ingenious, if not perfect classification, extensive erudition and classical purity of diction, must be ranked amongt the exclusive solidists. It is not surprising, therefore, that the profession in general should have bowed to the imposing authority of genius, or that it should require the combined operation of the powerful causes before enumerated, to disenthral their minds. A few eclectic and philosophical writers did indeed still continue to regard the fluids, as forming part of the diseased, no less than the healthy, human frame; and it is truly gratifying to be able to oppose to the name of Pinel that of Bichat. Unbiassed by any system, save that of nature herself, and possessing the most acute sagacity, his powerful mind could not fail to recognise and acknowledge the fact, that, although their influence had been overrated, the fluids do, in a great number of instances, undergo alteration, and furnish indications for treatment.* He was thus led to reject both exclusive solidism and humoralism, as a pathological no less than a physiological solecism.

In this country, solidism has been a favorite theme in our

*Anatomie Generale. Tom. I. p. 256.

schools, with the exception of that in our city. Both the former and present incumbents of the chair of practice of physic, have directed the attention of pupils to the occasional affection of the fluids in disease: the former, with, perhaps, an inordinate zeal, and to an extent not fully warranted by the state of our knowledge; but it must be confessed with much eloquent ingenuity, and very happy practical applications.* Eberle and Dyckman should not be overlooked, as having proved able champions of a limited humoral pathology.

Among the writers in Great Britain who have latterly cmbarked in the cause of the fluids, Dr. Stoker, of Dublin, deserves an eminent station. His views have been rendered so familiar, as to require no exposition. There are others entitled to attention, but we shall at the present time introduce two only, whose original notions respecting the state of the fluids, and more especially the blood, in febrile affections, have scarcely yet been made known in this country. We refer to Dr. Reid Clanny, of Sunderland, and to the author of the observations now under review. The former published a lecture about two years since, which he had previously delivered at the Sunderland Infirmary, on the composition of the blood in typhus fever; and on the light which his analytical researches throw on the nature or proximate cause of fever generally. By some invidious critics in England, it has been hinted that Dr. Stevens adopted his peculiar views at the suggestion of those of Dr. Clanny. This ungenerous supposition is entirely put at rest, by the fact, of which we have the highest official evidence, that Dr. Stevens not only adopted his present theory, but acted upon it, in practice, in the West Indies, several years since, and for a considerable period before the appearance of Dr. Clanny's paper. An exposition of their respective doctrines will further tend to prove their disconnection with, and independence of each other. This we shall now proceed to lay before our readers, after indulging in a few preliminary remarks, on what is known and established respecting the diseased condition of the fluids in the human body.

With the exception of a few-a very few, bigoted solidists, it is now pretty generally admitted, that the fluids may, and do often, become affected in disease. It is still a disputed point, whether they are ever so primarily; and the opinion of the great majority of physicians, is undoubtedly against such an occurrence. Passing over this vexed ground, it is important

Hosack's Medical Essays. Vol. I.

to ascertain how they are altered in their condition-in their quality, no less than their quantity.

The fluids then may undergo alteration, either in consequence of a change in the action of the organ or organs which produce them, or of a vitiation of the materials out of which they are originally formed. Neither of these morbid effects can, for a moment, be disputed by those acquainted with the state of the body, and of its secretions in disease. In the second case, the materials introduced into the fluid may be derived. either from without or from within, and the vitiation may likewise consist, either in a simply imperfect condition of the fluid, or in the super-addition of foreign and deleterious substances. Thus, alimentary matters may penetrate with the chyle into the blood, without having undergone a proper assimilation, and still preserving their distinct qualities; and once introduced in this manner, they must, of necessity, affect the properties and quality of both the solids and other fluids, with which they come in contact, or in whose composition they assist. It has, indeed, been denied, with no little degree of boldness and ingenious assumption, by one of the most eloquent and exclusive solidists of the present day, that any substances can, by possibility, enter the circulation. But this denial has long since been so triumphantly set aside, that to maintain it in the present advancement of medical science, savours either of wilful ignorance, or of blind prejudice.* The sources whence these foreign substances are derived, are extensive,-the gastric mucous membrane, acted on by all the ingesta; the respiratory passages, exposed to all the various impressions of the atmosphere, in all its different states of gravity, density, electrical condition, and impregnation with foreign substances; the skin obnoxious to endless external contaminations; and, finally, all their internal absorbing cavities. Thus numerous foreign materials may enter the circulating fluids, and cause in them important alterations. Examples without number might be adduced of the changes derived from each of the above sources, but they will readily and obviously suggest themselves to the well-informed reader. The other mode of change in the fluids, is simply their imperfect condition, in consequence of the materials out of which they are formed, being depraved. The opinion of the solidists to the contrary notwithstanding, it is certain, that inde

* Chapman's Therapeutics, vol. I. For a complete refutation of this able writer's chimerical doctrines on this point, see Review in 1st volume of the New-York Medical and Physical Journal. Also, J. B. BECK's notes to Murray's Materia Medica.

pendently of the action of the digestive or secreting organs, the composition of the fluids, say of the blood, must be affected more or less by the quality of the materials, which combine in its formation; so that a wholesome diet will more readily furnish pure chyle, and pure chyle be converted into more perfect and healthy blood, than unwholesome diet and impure chyle. It is, probably, in this latter point of view, that the fluids become deranged in febrile affections; and it is to ascertain, in what this derangement consists, what are its causes, and what the best means for its removal, that Drs. Clanny and Stevens have chiefly labored. The result of their attempts, by no means yet completed, shail now be briefly stated.

According to Dr. Clanny, the watery part of the blood increases in proportion during the progress of continued fever, while the proportion of each of the solid parts diminishes; and when the crisis has taken place, the opposite change commences, so that ere long the blood returns to its former condition. Dividing the period of an ordinary case of mild typhus, or synochus fever, into three stages of six days each, the first being the stage of increase, the second that of formation, the third that of declension,-he says he has found, from the average of many experiments, the following to be the proportions of the chief principles in a thousand parts of blood at the close of each stage.

In Health. 1st Stage. 2d Stage. 3d Stage.

From this table, it appears that all the animal principles, as well as the salts of the blood, decrease materially in quantity as the fever advances, and increase again as it recedes; and the author farther alleges, that the same changes do not occur in other febrile disorders.

Another change, which he says he has detected, is a diminution in the quantity of carbonic acid contained in the blood. In health, blood contains, according to his experiments, a sixteenth of its volume of that gas. In the advanced stage of unfavorable cases of typhus, it does not contain any; and in the intermediate periods, the proportion is found to decrease gradually, but he does not mention in what ratio.

Dr. Clanny infers from these premises, that contagious fever