on the Compojition of James’s Powder. 341 
two- or three grains of it at a time mixed with tartar. The 
opaque whitilh mafles, with metallic grains in them, thus ob- 
tained, being pulverized, were digefted and gently boiled in 
diluted nitrous acid. The filtered folution afforded nitre, and 
nitrous acid in a free Hate, the greateft part of which fuper- 
abundant acid being carried off, the lixivium did not whiten 
copper, or throw down any calx but iron with Pruffian alkali. 
The refiduum that refilled folution in nitrous acid was digefled 
and gently boiled in aqua regia . On {landing it was decanted, 
and this decanted liquid being heated, to carry off fuper- 
abundant acid and water, it afforded on mixture with water 
1,2 grain of Algaroth powder, and no metallic matter 
could be dete&ed in the water excepting a little iron. A final! 
part only being diffoived by the aqua regia y the refiduum was 
expofed to the flame of a candle with tartar as before ; and, 
by the aid of a lens, I could juft perceive two or three metallic 
grains in the fufed mafs. To this mafs the aqua regia was 
again applied, and o,,r 5 grain of Algaroth powder was ob- 
tained, and no other metallic calx was found but iron. A 
third affufion of aqua regia indicated an exceedingly minute 
portion of Algaroth powder ; but I could afterwards per- 
ceive no more metallic grains in the refiduum expofed to 
flame with tartar, nor obtain more Algaroth powder from the 
folution of the fufed mafs in aqua regia . The refiduum that 
refilled folution melted readily with a little phofphoric acid 
into an opaque, fomewhat yellowilh, white globule, not un- 
like calcined bone fufed with phofphoric acid, and a minute 
portion of flowers of antimony. The quantity, however, of 
this refiduum was fo fmall, that I defpaired of determining its 
nature further by more experiments* 
Having 
