an the Composition of J ames’s Powder. 329 
Solution in this menftruum, and ftill more to the wafts in 
•the paper filter, and to its adhering tp the retort when firft 
boiled. 
Thefe experiments indicated the fame kind of fubftanCes as 
the experiments with water, namely, calcareous earth in a com- 
bined ftate; phofphoric acid ; calx of antimony and of iron. It ap- 
pears alfo, that James’s Powder is either wholly or partially folu- 
Me in about 300 times its weight of concentrated acetous acid. 
III. With nitrous acid. 
'The 240 grains of powder remaining after the experiments 
•with acetous acid, p. .3 2 7. were digefted in the cold twelve 
hours, in three ounce meafures and a half of purified and con- 
centrated nitrous acid, diluted with four ounces of pure water, 
and then diftilled with a gentle heat till there remained about 
two ounce meafures. After {landing twenty-four hours, about 
one ounce and a half of clear liquid, which was very corrofive 
and acid, was drawn off by means of a fyphon. The turbid 
liquid and clofe white fediment remaining, being mixed with 
one ounce of diftilled water, were poured upon a filter of pa- 
per, and hot diftilled water was repeatedly poured upon this 
filter till it pafted through almoft taftelefs. The firft portions 
of the filtered liquid, in quantity ten ounces, being mixed toge- 
ther, were fet to evaporate in a glafs pan. As foon as the 
liquor grew hot, the turbidnefs difappeared 5 and as the evapo- 
ration went on, firft clouds, and afterwards portion sof fedi- 
ment, appeared in a clear liquid. The evaporation being con- 
tinued nearly to drynefs, a white, porous, or cellular cake 
was left, that weighed 129 grains. The liquid obtained 
Vol. LXXXI. Xx b 7 
