C i8 4 ] 
peaty matter, which had not been entirely feparated ; 
for when the experiment was repeated feverai times 
with different parcels of the blue, it appeared more 
or lefs foluble according as the black had been more 
or lefs perfectly feparated ; and when I added the 
vitriolic acid to a quantity of the black, though it turned 
it all of a brown colour, it only feemed to diffolve a 
quantity equal to the portion of blue, which ftill ad- 
hered to it. 
The nitrous acid, added to the blue powder, pro- 
duced pretty much the fame effedls, only the filtrated 
folution was of a much lighter brown. 
The fixed vegetable alkali diffolved alfo a confider- 
able part of it; but whether the whole or not, I 
cannot fay. The folution was an opaque brown li- 
quor, which did not become tranfparent after being 
twice filtrated, though it depofited no fediment upon 
ftanding feverai days. 
I added a fmali quantity of volatile alkali to it, 
which feemed to diffolve part of it, and turned the 
reft obfcurely green. 
To the folution in vitriolic acid, Ijoined fome fixed 
vegetable alkali : an effervefcence arofe, and a light 
curd of a colour between green and blue was thrown 
to the top, which foon iubfided, and became white. 
A fimilar precipitate was obtained from the nitrous 
acid, only it was not at firft thrown up to the furface 
in the fame manner as the foregoing. 
From the folution in fixed vegetable alkali, a red- 
difh brown precipitate was obtained, by the addition 
of vitriolic acid. Equal quantities of the blue powder 
and of black flux were mixed together, and being 
3 [ r ut 
