on the Composition of James’s Powder . 343 
infoluble In water and acids, and feemed to be of the fame 
nature as the fix grains of refiduum juft mentioned ( d ). 
I could only conclude from thefe experiments on this Info- 
luble matter, that it contained calx of antimony; but asto the 
proportion of it, and the other fubftance with which it is 
joined, I conjecture that it may be about half the quantity of 
the infoluble powder; and that the other half is antimonial 
calx and phofphorated lime, fo highly calcined and vitrified 
together as to refill folution in acid menftrua, decompofition by 
charcoal, and fufion with fixed alkalies, but not by phofphoric 
acid. 
I lliould not have been fatisfied with here terminating this 
analyfis without enquiring further into the nature of this info- 
luble matter ; but 1 difcontinued this analytic invefiigation in 
order to derive light from the fynthetic experiments which 
will be related hereafter. 
Thefe la ft experiments feem to (hew, that the proportion of 
antimonial calx is not fo great as might have been affigned from 
the experiments with nitrous acid, marine acid, and aqua regia . 
The fubftances and proportions of them, obtained from 240 
grains of James’s Powder, by the above experiments, are as 
follow : 
Grains. 
Phofphorated lime, with a little antimonial calx, 100, 
Algaroth powder, . . . . . 57,15 
Infoluble antimonial calx, with a little phofphorated 
lime, • * • • • • 10,85 
The fame infoluble calx, with, probably, a little phof- 
phorated lime, • « ® „ 55, 
Wafte, • .8, 
3 
240,0 
As 
