OCR Text |
Show 194 ON THE SLAVERY AND CoMMERCE latter CutiS, or true jkin. H~ncc they mull: neceffiuily have fuppofed, that, as the true jkziz was in every refpect the fame in all human fubjects, however various their external hue, fo the feat of colour mull: have exifl:ed in the Cuticle, or upper furface. Malphigi, an eminent Italian phyflcian, of the !all: century, was the firfl: perfon who difcovercd that the ikin was divided into three lamina, or parts; the Cuticlt, the tru~ jkin, and a certain coagulated fubfiance fltuated between both, which he difiinguiihed by the title of Mucofzun Corpus; a title retained by anatomifis to the prefent day : which coagulated fubfiance adhered fo firmly to the Cuticle, as, in all former anatomical prepa, rations, to have come off with it, and, from this circum!l:ance, to have led the ancient anatomifl:s to believe, that there were but two lamina, or divifible portions in the human ikin. This difcovery was fufficient to afcertain the point in quefl:ion : for it appeared afterwards that the Cuticle, wEen divided according to this difcovery from the other lamina, was femi-tranfparent; that the cuticle of or· THE HuMAN SPECIES. 1<)5 of the blackefl: negroe was of the L1me tranfparency and colour, as that of the purefl: white; and hence, the true jkins of both being invariably the fame, that the mucojitm corpUJ· was the feat of colour. This has been farther confirmed by all fubfequent anatomical experiments, by which it appears, that, whatever is thecolourofthisintermediate coagulated fubll:ance, nearly the. L1me is the apparent colour of the upper furface of the ikin. Neither can it be otherwife; for the Cuticle, from its tranfparency, mu!l: · neceifarily tranfmit the colour of the fobfiance beneath it, in the f.1me manner, though not in the fame degree, as the cornea tranfmits the colour of the iris of the eye. This tranfparency is a matter of ocular dcmonll: ration in white people. It is confpicuous in every bl uih ; for no one can imagine, that the cuticle becomes red, as often as this happens: nor is it lefs difcoverable in the veins, which are fo eafy to be difcerned; for no one can fuppofe, that the blue ll:reaks, which he confl:antly fees in the fairefl: complexions, are painted, as it were, on the furface of the upper lkin. From N 2 thefe, |