434 . . Foureroy’s Examination of 
ftance, not found in any other humours of the himwan 
body, nor in any of thofe of the bodies of the differtnt 
animals now known; a weak concrete acid, almoft mfolu+ 
ble, the principal folvents of which were the cauftic alkalies; 
that this particular acid very little hydrogenated and oxy- 
genated, but much charged with carbon and azot, was ay 
immediate produétion of the reins and of the diurefis, or 
of the formation of urine; that it was fometimes joined . 
with fome parts of the phofphats of lime, of foda, and of 
ammonia, with a colouring animal matter; but that thefe 
different fubftances, foreign to the lithic acid, feemed to be 
only acceffories, variable in their proportions, which might 
not have been found there at all, and which did not feem to 
_conftitute the particular effence of it. 
.Lmay add to this notice of my labours, which are already 
pretty old, that the experiments I have had occafion to 
.make for ten years paft on this animal matter, either for 
fome particular purpofe or in the courfe of my annual 
JeStures, by confirming me more and more in my former 
ideas, agreeing with thofe of Scheele and Bergmann, have 
only taught me that fome human urinary calculi contain 
phofphat of lime, infoluble in water and in pure alkalies, 
and. the alteration which the lithic acid experiences. by the 
aétion of the nitric acid when boiled in the latter—an altera- 
tion during which there is difengaged carbonic acid gas, 
‘ azotic gas, and the pruffic acid gas; fo that the calculous 
matier appears to me really to change its. nature during this 
action of the nitric acid. But all this ought not to change 
any thing of my opinions in regard-to the particular cha- 
racter and acid properties of the’ peculiar matter of the 
human urinary calculus. 
«<C. Fourcroy then afks, whether the Lalscins of Dr. Pear- 
fon have given different refults, and of fuch a nature-as fhould 
induce the French chemifts to give up their former ideas 
refpeCting the nature of the peculiar matter of the human 
‘urinary calculus ; or whether his experiments are fufficiently 
3 conclufive 
