‘406 ©AMenoir on the Uric Acid. 
forms the chief ingredient; of urinary calculi, 
there can be little room’ for doubt about refer- 
‘ing it to the class of acids. | 
Ist. Because’ it’ reddens the infisiots of 
litmus. It must be acknowledged: that Dr. 
‘Pearson has ‘given a contrary statement ; (7) 
but his result was probably obtained, by em- 
ploying a substance which had been precipi- 
tated by a deficiency «of acid. In that case, 
he must necessarily have operated not: on uric 
acid, but on a saturated. urate: so . closely 
resembling the acid, as not to be distinguish- 
able .by external. properties. . It), may, be 
alledged, indeed, that the uric, acid, which I 
employed, might retain a portion of, the ma- 
rine acid used for its precipitation; but this 
is not at all probable, since it was well edul- 
corated. by carbonate of ammonia. . Besides, 
the powdered stone itself produces the same 
effect; and certainly not from any mixture of 
super-phosphate of. lime, for, which, relying 
on the authority of Brugnatelli, (s), I have in 
vain sought in several specimens. of | uric 
caleuli. | . move 
2dly. Because it dhecpepliibes as Dr. Daew- 
Cr) Phil. Trans. 1798. 
(s) Ann, de Chim. xxv. 53. 
