C *8$ 1 
put into a crucible, were kept in a ftrong degree of 
heat for feveral hours : on being removed, and taken 
out of the crucible, the whole was found concreted into 
a fpungy mafs, the bottom of which was crafted over 
with fomething that had a kind of metallic appearance. 
This mafs was powdered, and the lighter parts 
wafhed off ; after which, a magnet was applied to what 
remained, and it attracted many of its particles 
ftrongly, without being brought in contact with them. 
Part of the white precipitate from vitriolic acid 
was mixed with a little fixed alkali, and being laid on 
a piece of charcoal, the flame of a candle was di- 
rected to it by means of a blow-pipe. It was thus 
kept in a red heat for about an hour, and on being 
removed, the magnet was applied to it, but none of 
the powder was attracted by it. The quantity that 
can be examined in this way does not exceed a few 
grains.’ 
To a finall quantity of the white precipitate, 
I added an infufion of tea j which turned it blue, ap* 
proaching to the original colour, but not fo deep. 
To another parcel of the fame, I added fome in- 
fufion of galls, and (hook them together. The liquor 
became of a dark blue colour, and what part of the 
powder remained at the bottom of the glafs was of 
the fame colour* This was not fo bright as that of 
the original powder diffufed in water, but entirely fuch 
as might be expected from the diffufion of it in a brown 
liquor like infufion of galls-, and, to fhew this, I poured 
fome of the infufion of that aftringent on the blue 
fubftance itfelf, and on (baking them together, they 
produced a colour aim oft entirely the fame. 
Vol. LVJIL Bb Aquan- 
