C TI 5 ] 
Nigredinis <^y£thiopum Caufam , &c. (a) : And I 
mult own I was formerly of that Opinion, thinking 
that the fulphureous oily Parts of their Fluids were 
more attenuated and exalted by the Heat of the Sun, 
and fo rendered black, as we know happens to Oil 
when well boiled, and to our Tongues in ardent 
Fevers. But this Opinion needs only to be well and 
more thoroughly confidered, to be confuted : For, if 
we confider the ill Qualities, and pernicious Eftedts to 
our Bodies, of any fuch exalted fulphureous Juices, 
no one will imagine that any Animal can live in 
Health, with any fuch Fluids in his Body 5 fince all 
the Fluids of the Body conftantly circulate, and com- 
municate with each other 5 for fuch fulphureous Juices 
feem to be the Caufe of black Tongues in acute Dif- 
eafes, and. of the Blacknefs of Gangrenes in fome 
meafure, which we: know foon prove fatal, unlefs- 
removed. Befides, thefe Juices muft be fecerned from 
the Blood, which feems to have no more Difpofition 
to turn black, in black than white People : And, as 
thefe black Juices lie in the Skin, it is very proba- 
ble, that they might often be exhaled, efpecially in 
Sweating ; and might leave the Skin deftitute of its 
black Colour, in fome meafure, at fuchtimes; which 
it never is, but appears rather blacker at fuch times, 
than any other. And as this Humour muft be fecerned 
from the Blood, and conftantly exhaled and renewed 
again, it is very likely, that it would be often ob- 
ftrudted in its Secretion, or altered in Colour, in fome 
morbid Cafes, like the other Humours, as well as 
(a) Epift. Anat. Edit . Londin. p. 26, 
evaporated 
