rm £263.75] 
VII. Examination of the Experiments and new Obfervations 
of G. PEARSON, M.D. on Human Urinary Concretions * ; 
and a Comparifon of the Refults obtained by that Chemift 
with thofe of SCHEELE, Bereman, and fome of tbe 
French Chemifls. By C..Fourcroy. From Annales - 
de Chimie, Vol. XXV IL. 
D R. George Pearfon, an Englifh chemift, well known by 
his very ufeful labours, and particularly his ingenious expe- 
riments on the decompofition of the carbonic acid, in his 
Experiments and Obfervations tending to fbew the Compo- 
fition and Properties of Urinary Concretions, inferted in the 
Philofophical Tranfactions for 1798, endeavours to prove 
that the calculi of the human bladder are compofed of a 
particular matter hitherte not well known to chemifts ; 
which Scheele, according to his opinion, negleéted to ftudy, 
and which he calls the wric oxyd. As this conclufion tends 
to overturn completely the difcovery of the illuftrious Swede, 
confirmed by Bergman, refpecting the acid of the human 
urinary calculus, and the refult of very numerous experi- 
ments which I fince made on that animal concretion, (a re- 
fult which ferved to confirm in many points the firft data of 
Scheele, according to which the expreffion of lithic acid had 
been adopted in the new nomenclature,) I thought it my duty 
to examine with particular care the long differtation of Dr. 
Pearfon. I was befides induced to do fo by the lively inter- 
eft which it is pretty generally known I take in every thing 
that regards the analyfis of animal fubftances ; and the more 
fo at prefent, on account of the refearches refpecting urine 
on which I and Cit. Vauquelin haye beén for feveral years 
employed. Inftead of finding ourfelves anticipated on this 
fubje&t by this able Englifh chemift; I was not a little afto- 
nithed to difcover in his differtation a great number ot affer- 
* For Dr. Pearfon’s paper on this fubjeét, fee Philofoph. Mag. vol. ii. 
p- 33 and 130. 
S 4 tions 
