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of the masterly dissertation prefixed by the author to his treatise.

The main objects of Dr. Good in the new system here exhibited are, to connect the science of diseases more closely than it has hitherto been, with the kindred branches of natural knowledge; to give it at once a more obvious and intelligible classification, and an arrangement more simple in principle, yet more comprehensive in extent; to correct its nomenclature, where it can be done without unnatural force; to trace its distinctive terms, both upwards to their sources, and downwards to their modern synonyms in various languages: thus producing "not merely a manual for the student, or a text-book for the lecturer, but a book that may stand on the same shelf with, and form a sort of appendix to, our most popular systems of Natural History; and may, at the same time, be perused by the classical scholar without disgust at that barbarous jargon, with which the language of medicine is so perpetually tesselated." The attempt is evidently a bold one; but it is throughout conducted with a becoming spirit, both towards the author's predecessors in the same region of inquiry, and with regard to his own qualifications for the arduous task.

In his preliminary dissertation, (occupying 100 pages) he describes, with great perspicuity, the chief nosological systems of modern times, the nomenclature in actual use, and the general nature of the improvements which he proposes to introduce. Speaking first of nosological treatises, he regards all their modes of arrangement as reducible to two classes, those of synopsis and of system; and decisively prefers the


latter, on account of the facilities which it supplies both with reference to study and to recollection. Of systematic arrangements, he briefly describes the alphabetic, that formed on the duration of diseases, that on the anatomy of the animal frame, that which is referred to the cause of diseases, denominated the etiological method, the mixed modification which rests on extent, sex, and infancy, conjointly, and then, the system built upon the distinctive symptoms, or coincidents of diseases,-this latter being, in his opinion, the only method which will generally hold true to itself, and on which entire dependence can be placed.

He next presents characteristic sketches in succession of the nosological systems of Plater, Sauvages, Linnæus, Vogel, Sagar, Cullen, Selle, Plouquet, Pinel, Macbride, Crichton, Darwin, Parr, and Young; and of the limited arrangements of Plench, Willan, Abernethy, and Bateman. In pointing out the nature, merits, and defects, of the several systems which are thus made to pass in review before him, he evinces a kind, courteous, and liberal spirit, developing, with obvious pleasure, the improvements which the author of one nosological scheme has made upon those which preceded, and marking those peculiarities which he has been able to incorporate with systematic propriety in his own arrangement. Several of the observations made by Dr. Good in these concise delineations indicate great logical acumen as well as philosophical research, and cannot but be perused with benefit by the student of medicine, or, indeed, of natural history.

ZúμTwμаrа from ovμriarw, "to fall in, happen together, or coin

Thus, when he notices Dr. Cullen's very extraordinary confusion of genera and species, he remarks that many other nosologists have fallen into similar mistakes. To prevent their recurrence, he subjoins the following instructive observations.

"A genus is not a disease, any more than it is an animal, a vegetable, or a mineral; but a group or assemblage of any of these, possessing certain like characters, and associated in consequence of such resemblance. The consenting characters being abstracted and put together, constitute the generic definitions, and apply to the whole; while the subordinate characters or coincidents, by which one differs from another, constitute the specific definition, and distinguish 1 from 2, and 2 from 3, of the same group or genus. A genus, therefore, is a mere abstract term, a non-entity in nature; highly useful, indeed, in the chain of orders, --but which can no more exist without species than a regiment or a regimental company can exist without soldiers. On this account it is that no man can ever discover a genus, though he may combine generic signs, and invent a generic name. The usual order is the following: he first discovers an individual, whether a plant, animal, or disease, possessing very peculiar marks, so as to separate it distinctly from any known individual, or groups of individuals. He may now, therefore, be said to have found a new species; and he proceeds next to arrange it. He first separates from it the most striking mark by which it is distinguished; and if this should be strictly singular, it constitutes alone a sufficient character for a new genus, and will form what is called, from this very circumstance, its essential generic character. If it be not strictly

singular, he must look for another striking character,a coincident or co-appearance,-or if necessary, in order to render the distinction complete, a third; and the generic character will consist in the union of these coincidents, in the combination of the marks that are thus first detached from the individual, and then brought into a state of combination. To this combination of detached or abstract signs he gives what name he pleases; and he thus obtains a generic name, as well as a generic definition. He then proceeds to select one, two, or more other marks, by which the individual is peculiarly distinguished; and these united form his specific definition, to which, in like manner, he adds a specific name. He has now discovered and identified a species, and formed and denominated a genus. His genus, indeed, consists at present but of a single species; and many genera never consist of more; but the genus is, nevertheless, formed upon a collective principle; it presupposes that other individuals may, hereafter, be detected, possessing the same generic character, and consequently belonging to the same banner; at the same time differing in several of its subordinate marks from the individuals already arranged under such banner; and which, in consequence, will produce new species as long as other individuals possessing such discrepancies shall be traced out." p. xx.

The second section of the preliminary dissertation, which is devoted to medical nomenclature, is taken principally from the essay on "medical technology," published in 1810. There are, however, some interesting additions in reference to matters of etymology, the precise original import of words, the extraordinary

changes which some of them have experienced in the lapse of time, and the radical absurdity involved in some current phrases, such for example, as tonic spasm, which is "literally extensible contractibility."

In the third section the author explains his main design in the present work, which is to attempt improvement in the healing art in its two important branches of nosological arrangement and nomenclature. He investigates the primitive and modified meanings of several words from a great variety of languages, and adverts to some of the evils which arise from their loose and vague use. He then ascertains the import of the common prefixes and suffixes employed in the technology, and shews that they are too often so introduced as to occasion confusion, where accuracy and precision are above all things desirable. The general inquiry, which he thus pursues into its several ramifications, is new, I think, not only in reference to medicine, but in great measure, also, to Greek philology. It cannot but be useful to the intelligent medical student; while it is, indeed, well calculated to gratify the general reader.

The author next proceeds to unfold the principles by means of which he endeavours to incorporate the elementary study of animal diseases, with that of the animal structure, or rather, with the animal economy. He decides to erect his edifice upon a physiological basis; and then sketches the plan which he proposes to himself and recommends to others.

The author had first to balance between two schemes that of Haller, who begins at the first and simplest vestige of the living fibre, and pursues the growing ens through all its stages of evolution; and

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