This matter is white and tranfparent in Europeans^ 
Mulatto esy black in Negroes-, and, in 
them all, vifible on the furface of their fkins. If, 
by a furgical operation, that kind of dime be taken 
out of a Negro’s fkin, the outfide will appear grey- 
ifli from the wound. 
Wherever this mucus or fluid is prefled down, it 
is leaft blackifli ; as we nriay obferve by the palm of 
a Negro’s hand. 
The fame obfervation is applicable to people 
attacked with the yellow jaundice, as will appear 
from the refult of an experiment upon two men 
dead of that diforder, whofe outward 'fldn refumed 
its former whitenefs, after having been waftied to 
let out the mucous body, that melted in water; be- 
caufe this die is, with refpe6t to the fkin, as fub- 
tkinccs reprefented by a looking-glafs, fince it 
throws out a greater or leflfer refleclion according 
to its lhades of light. 
But if, when diflblved, it be permitted to fettle, 
it will become black and folid again, — as we have 
obferved in the courfe of our experiments ; hav- 
ing collected a certain quantity of that matter by 
means of an ivory blade; yet, being lefs fluid in 
whites, it is not fo eafiiy found as it is in tome vege- 
tables. 
Such is the paint that Nature ufes to beautify all 
her works— the fliells of fiih, the feathers of birds, 
an4 
