236 VARIETIES OF COLOUR 



absorbents, or nerves. Therefore, though perforated by the 

 hairs, by the excretory tubes of cutaneous follicles, by the 

 cxhalant mouths of the capillaries, and possibly by absor- 

 bent orifices, it is incapable of sensation and all vital actions, 

 extravascular, inorganic. It is a protecting sheath for the 

 finely-organized and sensible skin ; and serves the further 

 purpose of preventing evaporation, by which that organ 

 would otherwise be inevitably dried. Thus the external sur- 

 face of our living machine is in a manner dead ; and ob- 

 jects applied to it act on the cuticular nerves through this 

 insensible medium. When preternaturally thickened, it 

 destroys sensation : if removed, as by blistering, the contact 

 of bodies gives pain, but does not produce the appropriate 

 impressions of touch. 



The cuticle, as well as the cutis, is nearly the same In the 

 white and the dark coloured races : it is, on the whole, 

 darker in the latter than in the former, and possesses a 

 grayish or brownish tint. If there are any other slight mo- 

 difications, they have not yet been ascertained. 



A third and more delicate stratum, interposed between 

 the epidermis and the true skin, and called the rete or reti- 

 culum Malpighii or mucosum, has been generally regarded 

 as the seat of human colour — of all the diversified tints 

 which characterize the various races of men. The softness 

 of its texture, and its perforation by hairs, papillae, &c. ac- 

 count for the name rete mucosum. 



It is a black layer, about as thick as tlie cuticle itself,or 

 even thicker, in tlie Negro ; and darker coloured on its der- 

 moid than on its cuticular surface. Putrefaction detaches 

 it with the cuticle from the subjacent cutis ; its further pro- 

 gress resolves the soft tissue into a kind of unctuous slimy 

 matter, readily washed away from the cuticle and skin. It 

 is not easily separated from the former : indeed it is, under 

 all circumstances, very difficult*, and where the skin is de- 



* SoEMMERRixG experienced this difficulty : he says, " It cannot, without 

 much trouble, be shewn as a peculiar detached membrane : and I could only 

 succeed in the scrotum in exhibiting considerable portions of it as a separate, 

 coherent, and independent membrane." Utbcr die Kbrpcrliche Verschicden- 

 heit des Ncgcrs vom Europdcr^ p. 45, 46. 



