[ *+ 8 ] 
fay Sennertus (a). So that if the Heat of the Sun 
will turn a white Skin fwarthy, as nobody in hot 
Countries can doubt, the fame Caufe might turn 
the fwarthy and tawny black ; for the EfFed feems 
to be the fame in one as in the other, and may 
therefore be produced by one and the fame Caufe. — 
As for the black People recovering, in the fame 
manner, their primitive fwarthy Colours of their 
Forefathers, by removing from their intemperate 
fcorching Regions, it mud be obferved, that there 
is a great Difference in the different Ways of change* 
ing Colours to one another : Thus Dyers can very 
ealily dye any white Cloth black, but cannot fo 
ealily difeharge that Black, and bring it to its firft 
Colour : And thus, altho’ the Skins of white, or 
even fwarthy People, are ealily affeded by the 
greater Power of the Sun’s Beams than what they 
have been ufed to, and thereby become black j yet 
they are thereby rendered fo thick and hard, or 
tough and callous, as not to be fo eafily affeded, 
or readily wrought upon, to render them again of 
their original fwarthy or pale 'Colour, by any of 
thole Caufes, as the Abfence of the Sun, Coldnefs 
of the Climate, or Ways of Life in it, which we 
have fuppofed to be the Caufes of the fair Com- 
plexions of the Europeans ; altho’, I believe, it has 
never been tried, what EfFed thefe luxurious Cuf- 
toms, or foft and effeminate Lives, which we have 
fuppofed to be the Caufes of Mankind’s turning to 
fo tender and delicate Complexions as the Europe- 
ans 
{a) Prax. Med. lib. v. part 3. cap. 1. 
