NOSOLOGY.
In order to reduce the practice of me dicine to something definite, to simplify what was perplexed, and to lay down cer tain general rules for a more accurate in vestigation of diseases, physicians in all ages have attempted to arrange these last into a systematized form ; and the works which have thus treated of dis eases are entitled Nosologies. We can not enter into an examination of those which have progressively been offered to the world in former periods, for this would carry us far beyond the limits prescribed by a Cyclopedia of any extent; yet while we are compelled to pass by the different arrangements of the Greeks and Romans, of the Arabians, the earlier Italians, and Germans, we cannot consent to relinquish a survey of those which are chiefly ap pealed to in the present day, and under which the art and science of medicine are generally taught in our public schools. We shall, for this purpose, select the five following, as affording a sufficient scope for comparison, and as offering the best arrangments of diseases which have hitherto been presented to the world : these five comprehend the nosological systems of Cullen, Sauvage, Linnzus, Vogel, and Sagar ; and we shall exhibit them in their respective classes, orders, and genera.
Nosological arrangement of Cuuss.
Our remarks upon these different ar rangements must be cursory. That of Vogel would appear at first sight to be the fullest, as comprising not less than five hundred and sixty distinct genera of diseases ; and that of Cullen the least complete, as extending to not more than a hundred and fifty ; but when it is re flected upon, that nearly five parts out of six of the distinct genera of Vogel are regarded as mere species of other gene ra by Cullen, and arranged accordingly ; the latter must at once be allowed to be equally full, and to possess a high advan tage in point of simplicity. Sagar's is the most numerous next to Vogel's ; and, like Vogel's, it is numerous, not from the pos session of additional matter, but from ex tending to distinct genera diseases of the same genus, and which ought to rank merely as separate species, or even va rieties. In the general arrangement of these nosologists, we perceive a consi derable resemblance to that of Sauvage their classes, though differently disposed, are nearly alike, as well in name as in num ber; yet Sauvage's is the most simple, at the same time that it is the most com prehensive. The arrangement of Linn mug
is, like all his arrangements, neat and clas sical, perhaps the most classical of the whole of those now before us. His sys tem is in a great measure his own : he has however more classes and genera, but fewer orders, than Sauvage ; and it is not always that the terms of his classes are sufficiently characteristic of the dis eases that rank under them. Many of those that are disposed under the class quietales, for example, are as much dis eases of the mind, as several that are plac ed immediately under the class mentales ; and we are afraid that the term dolorosi, peculiarly applied to Class IV. is just as applicable to a great multitude of dis eases distributed under other classes, as it is to the tribe which is thus connective ly arranged.
Of Dr. Cullen's table it is obvious that its chief features are due to him alone— his classes are for the most part simple, and at the same time comprehensive, his orders are natural, and his genera ably disposed. The most objectionable of his classes is the last, or that entitled locales, which, like the cryptogamia of Linnxus's botanical system, is a mere appendix, for the purpose of comprehending whatever could not be conveniently disposed un der the previous heads. There is also some confusion as to a few of his orders, and we may here enumerate profluvia in Class I. compared with apocenoses in Class IV. since the former is only a Latin, and the latter a Greek word of the same meaning ; and since the diseases in the former order are only distinct genera of the latter in many instances ; there is al so some doubt as to the situation of seve ral of his genera. Nevertheless, it is, up on the whole, the best division that has hitherto appeared ; it is far more gene rally studied and lectured from than any other ; and under this division therefore we shall proceed to notice, cursorily, the different genera, according to this classi fication, and to describe the character and mode of cure of the more common or more prominent.