42 On the Compofition and Propertics 
phofphates. As Scheele obtained an acid fublimate, it has 
been imagined by fome writers, that the precipitate by any 
acid (even by the carbonic) from the alkaline menftruum, 
was an acid; the fame as that obtained by fublimation, and 
which, in the new fyftem of chemiftry, has been denomi- 
nated lithic acid. The following experiments fhow that 
thefe fubftances are dificrent fpecies of matter. 
H. Experiments. 
250. grains of a white, fmooth, Jaminated, urinary calcu- 
lusy and the fame quantity of a nut-brown one, with an 
uneven furface, both of which were of a roundiff figure, | 
were pulverifed together *, 300 grains of thefe’ pulverifed 
‘ealculi were triturated with three ounces and a half, by 
meafure, or five ounces, by weight, of lye of cauftie foda. 
The mixture became thick, and copioufly emitted ammo- 
niacal gaz. After digeftion for a night, and then boiling, 
with the addition of five ounces of pure water, I obtained, 
by filtration, five ounces of clear colourlefs liquid. Boik 
ing water was repeatedly poured upon the ftrainer, till what 
pafied through it was almoft taftelefs, and remained clear, 
on the addition of diluted fulphuric acid. 
(2) The matter remaining on the firainer, being dried, 
was an impalpable, white, taftelefs, heavy powder, which 
weighed 96 grains. 
(6) The five ounces of filtrated liquid, having’ been. fet 
apart, on ftanding, depofited a white, opaque, granulated, 
foap-like matter, from a colourlefs clear hiquid. The liquid 
being decanted, the depofit was dried, and was then’ an 
apague, brittle, foap-like matter, which’ diffolved’ readily 
im ‘water, giving a clear but not vifeid folution, and 
= The objet of thefe experiments being principally to inveftigate the 
properties of one of the conftituent parts of urinary concretions, which 
part was previoufly determined (by the telt of nitric acid), to exift in both - 
thefe; it can be no objeétion to the experiments, that I made ule of a mix- 
ture of two calculi. i 
7 tafting 
