But whatever may be the immediate or remote causes of the Negro complexion, we can discover, at least, a most beneficent final cause of such an appointment. It was long ago uiscovered by Dr Franklin, that black transmits heat more readily than any other colour. The subject has been investigated with much more minute ness by Mr Leslie and Count Rumford. The former discovered, by a set of most conclusive experiments, that hot water, in vessels of the same capacity, bm of different colours, cooled fastest in those which were of a black or dark colour. And by taking a cubical vessel of tin, and coating one of the faces with lamp black, he found, by means of his very delicate differential thermometer, that much more heat was radiated or thrown off from the black side, than from the others which had been left clear, or which had been differently prepared. May we nut consider, then, the black colour m the human species, which is only found in the most scorching climates, to be a wise expedient provided by the Author of our nature, for cooling the fever of the blood under the in fluence of a tropical sun ? Wc hope what has been said will be sufficient to ac count for the varieties of colour in the human species. But had we even been unable to trace so accurately the operation of heat on the human complexion, had we found black and white men, indifferently, under the various de grees of latitude, or of heat, we would see no more ne cessity for supposing a difference of species, than for ap plying the same expedient to solve the phenomenon of white and black sheep in the same flock, whose pedigree can be indisputably traced to the same ancestors. rho isaricties, in this case, are evidently accidental ; though there is every probability that they might be perpetuated ; and some have thought that the varieties in the human complexion are of the same kind. This might do well
enough as an argument to make a stand upon, if others were wanting ; but we think we have already stated others more philosophical, and of more decided efficacy in their operation.
It is certain, however,that there are some very remark able accidental varieties in the human species. A very singular race of people is found on the Isthmus of Darien, whose colour is perfectly white, not, however, resem bling the white skin of Europeans, but the dead white of the Albino. These people produce children of the same complexion and appearance with themselves, though there is every probability that they sprung originally from the copper coloured Indians of the Isthmus : be cause it is observed that this is sometimes the case still; and two copper-coloured parents sometimes produce an Albino child nay, Albinos have often been born of per fect negroes. And it ought to be remarked, that all the children of ncgroes are born white, that the dark colour comes on in the course of a few months, and gradually deepens, in a course of years, into a glossy black. We have not, however, the same evidence of black children being ever produced from white parents, otherwise the hypothesis of an accidental variety giving rise to the negro race might be admitted ; though we cannot see why this should not take place, more than the other variety. Sec Buffon's Nat. Hist. vol. iii. Smith's Essay cn the Variety of Complexion and Figure in the Human Species. See COMPLEXION, for an account of the al gu ments for the other hypothesis. (g)