on the Compojifion of James’s Powder. 53 1 
(/) Pruffian alkali occafioned a light blue colour, but no 
turbid appearance till the mixture had flood feveral days, which 
was then flight. 
(§) No change of colour was produced on a copper plate. 
A little of the foft and deliquefcing part, juft mentioned to 
have taken place at the edges of the folid mafs, tailed bitter 
and four. It melted under the blow-pipe into a horny kind 
of globule ; but the dry part of this mafs could not be fufed 
by this means. 
This ounce and a half of folution being confumed in thefe 
trials, the fame quantity of boiling diftilled water was poured 
on the precipitate or part not diflolved by this quantity of 
water on the firft affufion. After ftanding and boiling, the 
precipitate appeared to be but little diminilhed. The clear 
liquid did not as before render lime-water turbid ; but a preci- 
pitate enfued with nitrated mercury, which on comparifon 
was found to be a more delicate teft of phofphoric acid than 
lime-water. This folution alfo, by this fecond affufion of 
water, did not as before grow thick with mild alkali of tartar, 
nor blue with Pruffian alkali. The fediment, undiffolved by 
thefe two applications of water, did not totally diffolve in a 
fuperabundant quantity of nitrous acid ; but completely and 
immediately in a fmaller quantity of marine acid; and this 
folution in marine acid, with a large proportion of water, pro- 
duced milkinefs ; with Pruffian alkali, it turned of a deep blue 
colour ; it did not whiten copper ; faccharine acid and falited 
barytes only {lightly difturbed its tranfparency. ^ 
By thefe experiments I found the folution of James s 
Powder in nitrous acid contained, probably, a pretty confi- 
derable proportion of calcareous earth united to both nitrous 
Xn atld 
