VOL. XLIII.] PHILOSOPHICAL TRANSACTIONS. 5S 



appear on the inner surface of this inner lamella ; these fibres being, as it were, 

 contracted within the two lamellae, on the external surface of this inner one. The 

 inner surface of the outer lamella of the epidermis, or at least of the outermost of 

 the two into which it is divided by cantharides, appears to be a whitish membrane, 

 like the other membranes of the human body; except the forementioned black 

 spots, which appear on this likewise, and the colour it receives from its external 

 black surface, which appears in some measure through the inner surface, and 

 makes the whiteness on it appear very superficial. This outer lamella is thicker 

 and tougher, and not so pellucid, as in whites. 



By scraping these lamellae of the cuticle of negroes, they may be made more 

 white, and these black spots scraped off, by which the under lamella will become 

 as white as any membrane almost of white people; and several white striae may be 

 scraped off from the outer lamella, by which both its surfaces will become nearer 

 of the same black colour : whence the cuticle would appear to consist of, or be 

 composed of, many different lamellae, and those of different colours, so that the 

 external one only is black ; which blackness is easily scraped off from the mem- 

 branes, by any thing that will abrade the fibrillae. 



Under the epidermis of negroes, when separated in a living subject, by blister- 

 ing, appears as it were a third membrane, between that and the cutis vera: this is 

 the corpus reticulare Malpighii, which differs from the same part in white people 

 in two respects; for in negroes it is of a black colour all over the body, where they 

 appear black; and whereas, in white people, it is of a soft, pappy, or mucous 

 substance, and can hardly be separated but in pappy flakes, in blacks it is separated 

 very often, by the force of epispastics, from both skin and cuticle, and may often 

 be peeled off, like a membrane, from the cutis, as the epidermis is from it; while 

 in other places, by a less force of the epispastic, it is closely adhering to the cutis, 

 as the epidermis itself often is: this membranous expansion is of a much thicker 

 substance, or denser texture, than the game part in whites; and from this seem to 

 proceed the black fibres, which pervade the epidermis, and end in its external 

 surface. 



The cutis itself, which lies under this black membranous expansion, and to 

 which it is closely connected, is of a white colour in negroes, somewhat like the 

 skin of many brown-skinned white people; but when this black corpus reticulare 

 is on it, after the epidermis is separated, they ajjpear, when both connected to- 

 gether, of a brown copper-colour, somewhat like the colour of an Indian or 

 mulatto ; some of the colour of the white skin below being transmitted through 

 this thin black membrane : which seems to show, in what manner the colour of 

 these Indians and mulattoes may be occasioned, by the colour of the white mem- 

 branes under their cuticles appearing partly and imperfectly through them, as the 

 white skin does through this coi-pus reticulare. 



