OF TEMPERAMENTS AND VARIETIES liEsinEs these differences in the form and structure of the brain and the contiguous parts, there are other origi nal differences, of a more decided and less equivocal na ture, in the general organization of the body. When these belong to a certain number of individuals only, they are styled temperaments ; but when they exist in large communities, and appear to be attached to peculiar coun tries or climates, they are termed varieties. The ancients were very attentive to the discrimination of temperaments, and traced out their distinguishing features with consider able acuteness. A large part of the pathology of Hippo crates and of Galen is founded upon the supposed know ledge of temperaments, and of the influence of external agents upon them. As is usually the case on these sub jects, we find, in the writings of these authors, a mixture of correct observation with false hypothesis. The four temperaments were formed upon the principle of their be ing a disproportion between the four constituents of the blood, and they were accordingly named, sanguine, cho leric, phlegmatic, and melancholic—names which are still retained, although the hypothesis whence they were dc rived has been long discarded.
Various writers among the moderns have formed clas sifications of temperaments, some professing to proceed entirely upon new observations, while others have taken Hippocrates's arrangement for their basis, only attempt ing to adapt it to the modern improvements in science. We conceive that there is a real foundation for all the temperaments of Hippocrates, although, as they depend upon such very erroneous opinions, it may appear absurd to retain the old appellations. We should be disposed to substitute for them the following, vascular, tonic, atonic or relaxed, and muscular, corresponding to those above mentioned, and, if we add to these the nervous, after the example of Dr. Gregory, we conceive that we shall pos sess a ei.00iritation, in which we may arrange all those individuals who possess any peculiarities that are suffi ciently well marked, and are, at the same time, common to any number of individuals. The cause of the different temperaments may be attributed partly to an original dif ference in the physical structure of the body, and partly to a difference in the powers of contractility and sensi bility. Without going into minute detail, we may con ceive of the vascular temperament as depending upon the fluids existing in too large a proportion to the solids, while, at the same time, the system possesses a considera ble share of both contractility and sensibility. The tonic temperament appears to he the one in which the structure of the body, as well as its appropriate powers, are the most correctly balanced, while in the relaxed or atonic, we have the excess of fluids, as is the case in the vascu lar, but along with this, a deficiency of both contractility and sensibility. The muscular and the nervous temperaments
derive their respective characters from the disproportion between these two powers, the first having an excess of contractility, and the second of sensibility. Few indivi duals possess these characters in the extreme degree, and in those cases where they have been the most strongly marked by nature, education, peculiar modes of life, and various other causes, have so far modified or counteract ed them, as materially to diminish their effect, but still there appears sufficient ground to admit of their exist ence, as entering into the original elements of our consti tution.
The classification of mankind into the different varie ties, and the description of the circumstances in which thcydiffer from each other, belong rather to the province of natural history or anatomy than to that of physiology ; but there are some points connected with the subject which will properly fall under our notice. And the first, as well as the most interesting inquiry which presents it self, respects the common origin of the different varie ties ; whether, for example, the European and the Afri can proceed from one common stock, or whether they are derived from different parents, each of whom were pos sessed of the characters of their respective descendants ? The above question is one of very difficult solution, in which we have little to guide us except doubtful analo gies, and considerations which apply only in an indirect way to the subject under consideration. In the first place, it may be remarked, that we are not acquainted with any natural causes, now in operation, which would appear adequate to effect the change in question. It is also as serted, that from the earliest records of history, the same varieties existed among the individuals of the human species as at the present day.* Nor do we see those gra dations which might have been expected to take place, were the varieties the mere result of external causes, which may be supposed to operate upon the human body in all different degrees. There are likewise instances of tribes belonging to different varieties living in the same country, and even pursuing the same habits and modes of life, yet where they each of them retain their peculiar character, without any approach to the production of an intermediate species.