Much of the confusion of ideas and erroneous conceptions of disease has arisen in past times from the natural imperfections of language; no doubt somewhat too is to be attributed to a conventional laxity in the use of terms and forms of phraseology, furnished by obsolete analogies, and hypotheses which can no no longer be regarded as tenable by the highly educated physician of the present day. In some respects, the language and hypotheses employed in the description of disease, and which are known to be false in fact, bear close resemblance to, and forcibly remind us of, the use still made in astronomy of forms of expression derived from the long exploded theory of the Sun moving round the Earth, and the explanation, and even computation, of many phenomena of the Heavenly bodies from their apparent motions. It is thus that the apparent forces of a fever, inflammation, or other diseased state, are assumed in medical language to perform active and self-dependent motions in, upon, or around an imaginary central and unmoved body, the human frame, while more close inquiry satisfies us that the apparent active motions of the fever or inflammation are but subjective phenomena, being the results, and so far the exponents, of the direct motions of the various parts of the animal organism. If accepted as a well understood and acknowledged conventionalism, in which, to avoid periphrasis, and for the convenience of familiar exposition, the apparent motions and actions of imaginary entities played the part of the real or direct motions of the various members of the animal organism, the hypothetic language and terms of medicine would be free from practical objection. But unfortunately it is almost universally the case to find the apparent taken for the real, and the most utter confusion of ideas prevailing as to the part performed on the one hand by disease (in its assumed capacity of an independent self-existent entity), and on

had himself completed the anatomical description of the valves of the veins. In addition to all this, which constitutes the essential knowledge for arguing to a circulation, it may be asserted (but cannot be proved in our present limits, or without going fully into an exposition of his views and works), that Ruini possessed as complete and full a knowledge of the circulatory apparatus and the circulation of the blood itself, as that of Harvey subsequently elaborated.

Now it may be asked, if Harvey had remained in England, and prosed with colleges of physicians, and fawned upon royal patrons, what would be now known of his name or labours? and what would he have done to complete the knowledge of the circulation of the blood? The answer is obvious. Without Harvey's intervention in any manner, the discovery of the circulation was already assured to science by a multiplicity of experiments and observations amongst the fertile schools of Italy; on the other hand, without Padua and Fabricius, Harvey's was a name destined for no distinction. Be it understood, however, that we honour him not the less for what he has done, and for his most able and energetic advocacy of a cause which, without such aid in northern Europe, would doubtless have been slower to find recognition in schools wedded to older dogmas.

the other by the animal organs and functions. Now, not only is this a state of things inconsistent with the requirements of science and unworthy of the educated members of a highly scientific profession (or what ought to be such), but it leads, in not a few instances, to errors of a practical kind, and of grave consequence, in clinical medicine. While the faculties of the physician are absorbed in watching the vagaries of the assumed avтокpárea fever, which it is impossible to reduce to a connected and consistent train of action, amenable to rational processes of medication, he is not in a position to command for himself a true insight into the workings of the various parts of the human machine in its abnormal condition of action, or to form a proper appreciation of the means likely to restore the physiological equilibrium of the system. What has such loose, vague, and ill defined pathology produced in Practical Medicine, but in too many instances a hap-hazard use of nostrums, taken from a chance-medley Materia Medica on the faith of an "experience" which at best can only be regarded as an illustration of illogical argument from particular to general?

It is only, as well remarked by Henle," when empirical medicine, dissatisfied with the therapeutical results hitherto obtained, feels obliged to attempt new methods of treatment, that it will put itself under the guidance of its twin-sister (rational pathology), rather than linger under the disgrace of that lamentable inefficiency which seizes upon anything fortuitous, in order to experiment hap-hazard upon some victims, too few for profitable results, many for a tender conscience"!!

too

In the actual state of medicine, it is extremely difficult to point to any concrete body of opinion which can be taken as a fair exponent of the pathological doctrine of disease, generally adopted in the present day.

It is difficult to do this, not only for the science of medicine at large, but even for any one individual school; it is not difficult to attack this dogma or that, referring to an individual disease, and show its fallacies; but it is almost impossible to summarise the various theories of discase still in vogue, for the object we have in view. The opinions which we purpose to combat with respect to the "entity" and individual personation, so to speak, of disease, are (in the literature of our day) to be gathered from the use of incidental terms, and the implied rather than expressed possession of special attributes on the part of disease. Though, perhaps, nowhere so categorically expressed in the medical literature of our own age, it can hardly be denied that such a disease as fever, for example, is regarded by many writers, and commonly in the minds and language of medical men, holds a place as an entity, for a time swaying the human frame, almost as

distinct as when likened by Paracelsus to a demoniacal archeus, who, from without, entered into, and in his distempered rage shook, the fevered body with the physical impulse of an independent power. And even those who will accept the more advanced pathology of fever, still see in cancer, tubercle, or syphilis, an incontrovertible proof (as they hold it) of the specific nature of disease, of its independent attributes, of its analogy to self-existent parasitic organisms, and finally of its being something imported in globo from without, and superadded to the human frame, which had no previous existence in or upon it, and the effects, motions, and actions of which have no relation or analogy to those of the parts of the healthy body of man. In their views, pathological entities of disease become multiplied with every addition to the nosological scale.

It may be said, doubtless, that pathological anatomy and pathology, as cultivated within late years, have done much to dispel these mists of error, and to show us what diseased states of the human frame really are in all their forms and phases, however various. Much has unquestionably been effected in this respect, but it is only a small fragment of the great work which has to be accomplished before a rational pathology finds general acceptance in medicine. And it is not without importance to remark, that even now the prosecution of pathological anatomy is not unfettered by the continued acceptance of the doctrines of diseased entities and types and Morbid Species so-called.

All the considerations bearing on this subject are not without the highest scientific, as well as practical importance. If we adopt the view, that diseases have their own essential nature, their own attributes, parts, periods, and times, not only must our pathological doctrines be made to square with the current theories of disease, but therapeutics, as a scientific application of means to ends, must have the same limits. If, for example, fever be a thing from without, seizing on and implanting itself in the frame of man, the duty of the physician is forthwith to attack and expel the interloper vi et armis; or it may be considered that there is an internecine warfare between the autocratic entity disease, on the one hand, and the animal economy on the other, in which art sides with humanity, and both give battle to their common enemy. Pathology, not less than humanity, however, not unfrequently suffers from this alliance, and instead of the fever-demon, life is expelled, or perhaps both conjointly. No pathological views so much encourage the too often fatal "nimia diligentia medici".

Under another point of view, that indicated to us by rational pathology, fever comes to be regarded as a complex or aggregate

III.

15

of phenomena, arising with intelligible relation of cause and effect from certain derangements in the force and intensity of normal functions, the order and sequence of which it is in our power to trace with precision. Fever is then a series of effects from known causes, and these causes are none other than those which operate in the body in health. Therapeutics have now another end and object, namely, to regulate and control, diminish or arrest, the undue actions in the system, while, at the same time, the forces of the economy are maintained, stimulated, and supported, as occasion may require, or the increased wear and tear of the system demand; in a word, medicine intervenes as an art, with means directed to restore the physiological equilibrium which constitutes health.

This is but one example, and but one class of considerations; the subject is fertile with others of no less importance. If, for instance, it be once established, for disease in general, as well as for its so-called individual genera and species, that, instead of possessing a specific nature, independent existence, special and defined courses, and propagative forces, and instead of being endowed with inherent powers of destruction, they are to be regarded as only subjective phenomena, the exponents of increased or otherwise deranged normal actions, we at once, and for ever, get rid of the category of incurable diseases; such scourges of humanity as leprosy, tubercle, cancer, syphilis, small-pox, the plague, yellow fever, cholera, and the like, fose half their terrors, and a new era of hope opens up for suffering humanity. Medicine, as an art based on scientific research, secs new triumphs before her, and rises to a sense of increased dignity, in anticipation of curative results, possible though remote. Of the ills that flesh is heir to, she sees none with which she may not grapple. What stimulus is not thus offered to the clinical physician for renewed research into the intimate structure of tissues, and the study of function, under physiological and pathological aspects! As all known actions of the human system are under the control of art within certain limits, and these chiefly limits of time, from the first moment that the physiological equilibrium is disturbed, the medical problems, even in cancer, are confined, and this is logically demonstrable, to early diagnosis, and the selection of appropriate therapeutics. When, in fine, such a disease as cancer ceases to be a specific morbid organism, it is of necessity removed from the list of incurable diseases, and comes logically within the domain of curative art. Let us not, however, be misunderstood; logic here anticipates art; it points out the possible, not the immediately practicable. But even this is an immense gain. Once scientific research is on the right path, it is but a question of time to realise results available for practice.

We may now proceed to consider what disease is, and in what aspect a strict and logical science warrants us in regarding the various forms and so-called types of disease, which manifest themselves in the human body.

It will be a seeming paradox to affirm, as the shortest way of expressing the proposition which lies at the bottom of our present considerations, that Disease is not anything; in other words, that the so-called essential diseases-as fevers; the specific diseases— as cancers, tubercle, syphilis; the particular diseases—as inflammations; the so-called morbid products-as lymph, pus, ichor, succus cancri, cancer-cells, tubercle-corpuscles, and so forth, have no independent existence; that we are in error in regarding them as self-existent pathological entities; in fine, that while the most advanced histological research demonstrates the existence of well-defined and persistent physiological types in the structural elements of the human body, the same means of inquiry show us, with equal certainty, that no independent types of pathological structure can be proved to exist.

These views may, perhaps, be still more expressly stated and more clearly illustrated as follows. The plastic forces operating in living organisms produce minute structural elements, of definite shape and size, which possess distinct and well-individualised physical properties, and, in several modes of aggregation, enter into the formation of the various tissues. We thus have, to take the most striking case, in the egg undergoing the process of incubation, blood-corpuscles, bone-corpuscles, sarcous elements (minute structural elements of muscle), fibrous tissue corpuscles, nerve-tubes and cells, formed from a fluid of highly complex chemical composition (white and yolk of egg), originally containing only the most minute and fine granulations, but otherwise homogeneous. The structural elements thus formed (bloodcorpuscles, bone-corpuscles, etc., etc.) retain the character of individuality originally impressed upon them; no one of them passes into another in any further process of change. And with such regularity and precision do these various tissue-elements conform to the original type on which they have been developed, that it is found that in numerous instances, specific differences in size and shape are observable in the tissue elements in different classes of animals. This holds in an especial manner, as is well known, with respect to the blood and bone-corpuscles. Thus, the blood-corpuscles are of the shape of circular discs in all the great class Mammalia, with the exception of the camel, and dromedary, in birds, reptiles, and fishes, the corpuscles are elliptical in shape. Remarkable differences in the diameter of the blood-corpuscles have likewise been observed. In the size