ON THE COMPOSITION OF JAMEs' POWDER. 157 
Antimonite of lime with some superphosphate, 2.25 
Sesquioxide of antimony, .... 9.8 
Antimonious acid, ...... 34.21 
Phosphate of lime, 53.21 
99.47 
Loss, . . . r . .53 
100.00 
The experiments were all carefully repeated, and the results 
always approximated within a feiv tenths of a grain in the 100 
parts. 
I likewise endeavored to determine the amount of phos- 
phate by precipitating the phosphoric acid by lead. The re- 
sult was so near as to confirm the statement given above, but 
the process is more tedious; and as the phosphates of lead are 
known not to be always identical in composition, I preferred 
estimating the phosphate of lime by ascertaining the quantity 
of the base. 
Finding thus that the James' powder contained a propor- 
tion of sesquioxide of antimony, 1 repeated my experiments 
with other specimens of the powder, and found, that though 
all of them seemed to consist of the same ingredients, yet none 
of them contained these in similar proportions. Thus, with- 
out entering into details, I found another sample of this same 
James' powder to contain 2.8 per cent, soluble in water, 4.86 
of sesquioxide, (only about half of what was found in the 
other specimen,) 40.82 antimonious acid, — the phosphate of 
lime which constituted the remainder being almost the same 
in quantity as in the other. 
I then examined a specimen of James' powder prepared by 
Messrs. Newberry, and its composition appeared to be 3.4 so- 
luble in water, 2.89 sesquioxide of antimony, 43.47 antimo- 
nious acid, and 50.24 phosphate of lime. Of the part soluble 
in water a very small proportion only seemed to be antimonite 
