We trust it will sufficiently appear from the facts which have been stated, that colour is a superinduced habit, and that no particular shade of it can be regarded as an in separable adjunct of human nature ; and when we ob serve that a white nation is never found under a fervid sun, nor a black one under a moderate temperature, it is impossible not to ascribe the difference of colour in the human species to the variations of climate, with the other accessaries which have been specified. There is no sud den transition of colour, no definable line of demarcation; but we observe the shades gradually deepening or mel lowing, according as the countries are exposed to a vio lent or a moderate heat. This completely destroys the argument, that a particular race different from the rest of mankind, was necessary to people the torrid zone ; on the same principle it might be alleged, that as many se parate creations were necessary, as there are degrees of latitude from the equator to the poles.
There are indeed certain plants and certain animals, confined, by the constitution of their nature, to particu lar districts of the globe, and which cannot thrive beyond these limits. But nothing is more obvious than that the same species of men can exist, thrive, and multiply in every part of the known world, after their constitution has undergone that kind of transformation which is ne cessary to adapt them to their new situation. In fact, the very circumstance of man's being burn without any na tural covering or defence against the injuries of different climates, shows that he is intended as an inhabitant of all; and the Author of his nature has given him the power of adaptation, both in the resources of his own ingenuity, and in those insensible changes which are effected in conformity with the laws of nature, over which man has little or no controul. In the latter case, lie enjoys no higher privilege than the bounty of heayan has conferred on various species of animals whicn arc found indiffer ently in various climates ; but have different colours and appearances, according to the situations in which they are placed. Thus, hares, squirrels, and weasels, are white in northern latitudes, but brown or gray in milder climates. They are even found to vary their colours in the same country, according to the different degrees of heat. In Sweden, for instance, the hares are gray in summer, but perfi ctly white in whiter. Lepus apud nos, says Linnzeus, estate cincreus, hieme senzper a/bus. And
in still higher latitudes, when the cold returns, both birds and animals assume vie livery of winter.
Why then should we not expect to find the same va riations in the skin of the human species ? It is no ano malous appearance; it is the general law of nature, and we should have greater reason to be surprized did we find man an exception. It is impossible to assign any other cause for these varieties of colour than this, that sue h is the w ill of the Author of nature. The scat of colour in the human species has indeed been ascertained. It has been found that the skin consists of three lamina or layers, the outer or scarf skin, the inner or true skin, and a substance interposed between them, which, from its nature and appearance, has been called rat mucosum. This is found to be the seat or colour, the outer and inner portions of the skin being found the same both in black and white people. This substance is found to be black in the negro; reddish in the Mulatto ; brown in the Gypsey; white, with a slight shade of red, in Europeans ; and of a dead white in the Albino ; whilst in all these instances, the epidermis or scarf skin is perfectly white. But this is only an additional fact; it is no explanation of the phenomenon.
If we can trust the accuracy of I3arrere's observations, as stated in his Dissert. 8ur la couleur des .A^egres, we may perhaps go a little farther, and ascertain the imme diate cause of the black colour. He supposes it to be owing to the colour of the bile, which, from several dis sections of negroes which he made in Cayenne, he af firms to be as black as ink ; and as an effusion of the bile in white people tinges the skin of a yellow hue, the same effusion in negroes will make the skin perfectly black. This is, no doubt, a curious fact ; but why should the bile be constantly effused so as to tinge the skin in black people, whilst this happens only occasion ally in the case of others ? And were we to suppose, with Buffon, that both the bile and blood of Negroes arc much blacker than in the case of other persons, and that the blackness of the skin is owing to these circumstances, this would only be removing the difficulty a step farther back ; and it would still remain to be enquired, to what this blackness of the blood and bile is owing. In the present state of our knowledge, we must be content to ascribe it, generally, to the heat of the sun, without be ing able to explain how the effect is produced.