[ >21 ] 
Ibelow it : So that we muft look upon the Epidermis 
of white People to be a tranfparent Pellicle, of too 
Tubule or rare a Subftance, and too minutely divided,, 
to relied any Rays of Light from its Surface* but 
confiding of Numbers of Pores, which readily tranf- 
mit thofe Rays, through its thin and rare Subftance, 
by which it Ihews the Colour of whatever Parts are 
below it i on which the Colour of white People 
depends. 
But, as there are Numbers of Scales, or feveral 
Strata of fcaly Lamella in the Epidermis , fo this 
Tranfmiflion of the Rays of Light, from the fubcu- 
taneous Parts, muft be imperfed, fomc of thefe Rays 
being intercepted in palling thro 1 the feveral Lamella ; 
and the thicker the Cuticle is, i. e. the more there 
are of thefe Lamella , or the denfer their Texture, the 
more the Light will be intercepted in palling them, 
and the more the Colour of the Skin will degenerate 
from the pure White of the Membranes below it. 
This is agreeable to Experience for Mr. Cowper 
tells us, in his Anatomy, That the Thicknefs of the 
Skin proceeds from the Number of the Strata or 
Layers of Scales which compofe it : And we may daily 
obferve, that thofe who have fuch thick and coarle 
Skins, are never of fo perfed and pure a White, as 
they who have a thin and fine Skin (as {a) Cowper ob- 
ferves). But the Reafon why fuch thick-skinn’d Peo- 
ple appear of a yellowifh or tawny Colour, will be 
plain, from Newtons Obfervations (Opt. lib. II. p. i. 
Obf. 9. and 20.) ; where he fhews a faint yellowifh 
(«) Cowp. Anat. Tab. IV. 
Q_ 2 
. Colour 
