[ ..6 ] 
evaporated fometimes ; which however we never fee 
it to be. 
But, however well received this Opinion maybe, 
as being confident with common Notions, yet it is 
very unphilofophical to aflign any thing as a Caufe, 
which does not appear to exift ; and I believe that none 
* will be able to fliew the Exiftence of any fuch black 
Humour in the Skins of Negroes ; for their Sweat, or the 
Water in their Blifters, which would probably contain 
fome of this black Humour, was there any fuch 
thing, is as clear and white as in white People : 
Befides that the Exiftence of any Veflels in the Skin, 
which are fuppofed to contain this Humour, is not 
well agreed to by Anacomifts. Mr. Cowper fays, he 
never could find any fuch, altho’ carefully fought for (a); 
and none elfe have ever been able to fhew them : For 
the common Anatomifts take the Corpus reticulare to 
be a mucous Subftance, as they call it, which ferves to 
lubricate the Papilla nervofie , and contains this 
black Humour j but, altho’ it is of a foft pappy Sub- 
ftance in Whites, yet it cannot be called a fluid 
Mucus , any more than the Subftance of the large 
Nerves, or of the Brain, from when it arifes, and 
which are of a fofter and more mucous Subftance 
than it; befides that, in Negroes, it ftiil more refem- 
bles a folid Membrane, being to be torn off like 
the Epidermis ; and as it arifes from the nervous In- 
' valuer a , or Expanfion of nervous Fibres, it probabiy 
contains no Fluids, or none but what are moft pel- 
lucid and clear. 
(a) Tab. Anac. IV. 
Moreover, 
