C '3' ] 
whence we may juftly infer, i. That there is not fo 
great, unnatural, and unaccountable a Difference be- 
tween Negroes and white People, on account of 
their Colours, as to make it irnpoflible for both ever 
to have been defeended from the fame Stock, as 
fome People, unskilled in the Doctrine of Light and 
Coiours, are very apt too pofttively to affirm, and, 
without any Scruple, to believe, contrary to the 
Dodrine (as it feems to be) of the Sacred Pages, 
2. That the Epidermis , befides its other Ufes, tends 
to prelerve the Uniformity of the Colours of People 
throughout the World. 
Proposition VII. 
The Influence of the Sun , in hot Countries , and the 
IVays of Life of the Inhabitants in them , are the 
remote Caufes of the Colour of Negroes, Indians, 
&c. And the IVays of Living, in UJe among molt 
Nations of white ' People , make their Colours 
whiter, than they were originally , or would be 
naturally. 
My Defign in this Elfay was, not to treat fully of 
every thing relating to the Caufes or Effects of the 
Colours of People, but only to inquire into the par- 
ticular Make and Structure of the Skin, by which it 
comes to appear of fo many and fo diverfe Colours 
in the different People of the World 5 and to explain, 
from Newton's Do&rine of Light and Colours, in 
what Manner thefe different Colours are produced 
from this particular Make and Structure of the Skin , 
which is, what I take to be, the grand Queftion re* 
lating to the unknown Caufe of the Colour of Ne- 
groes 5 which has been often attempted to be deter - 
4. mined, 
