Dr. Pearfon’s Experiments on Cniculi. 269 
rendered turbid by the addition of the fulphurie acid, which 
forms with it a fulphat of lime; the fupernatant liquor, 
when evaporated, leaves the phofphorie acid after feparating 
the ‘nitric acid by evaporation. The nrine of diftafed pers 
fons is more’ acid, and contains more phofphat of lime, than 
sand of healthy perfons. 
” Xv It refults from all thefe fa&s, fays Side in eon= 
chide his differtation, that urine, independently of the 
fubftances already known, viz. the muriats of potafh, foda, 
and ammonia, the phofphat of foda and ammonia, and.an 
oily extractive matter, contams a concrete acid, -hitherto 
unknown, (which forms the urinary calculus,) amd: phof- 
phat of lime. 
I have mentioned with accuracy, and without omitting 2 
fingle experiment, the labour of Schecle, becaufe it appeared 
to me neceflary to do fo, in order to eftablifh an eafy and 
precife comparifon between his experiments and thofe of . 
Dr. Pearfon. 
The difcovery of Scheele, communicated to the Academy 
of Stockholm, was confirmed by Bergman, who gave, under 
the title of an addition, a memoir containing his own ex- 
periments on the ftone of the human bladder, with which 
‘he was occupied at the fame time as his pupil and friend; 
-and it may be readily perceived what muft be the weight of 
‘the aflent of that celebrated man, who firft introduced into 
"the defeription of chemical phenomena, and the reafoning 
on them, the purity, precifion, and method of the geome- 
tricians. In announcing that his experiments eonduted 
him to the fame conclufion, viz, that the urinary concretion 
was compofed chiefly of a particular acid; he fays he found 
fome differences, which, though he aferibes them to thofe of 
fubftances which they had both examined, were, however, 
‘found in all thofe which he treated. It is of importanée 
that I fhould relate here the differences obferved by Bers 
man, becaufe they may ferve to explain thofe which were 
oblerved by Dr, Pearfon himfelf, and which led him‘ to 
draw 
