270 -. Fourersy’s Examination of -~ 
draw a conclufion contrary to that of the illuftrious Swedith 
chemifts whom he combats in his memoir. 
t. Bergman never fucceeded fo far as to diffolve com- 
pletely urinary concretions in diftilled water, or in the nitric 
acid; but at the fame time the greater part was diffolved in 
the latter, efpecially when precautions were taken to employ 
an excefs of the folvent, fragments of calculus inftead of 
powder, a veflel fufficiently fmall to permit the infoluble 
matter to be collected; and by keeping the matters at a heat 
near that of boiling water, there was feparated a white 
fpongy matter, on which water, alcohol, acids, and am- 
monia had no action; dividing itfelf mto very minute par- 
ticles by ebullition, though ftill infoluble; giving by fire a 
coal difficult to be incinerated, and of which the afhes were 
infoluble in the nitric acid. He never had enough of this 
fubftance to enable him to become better acquainted with 
its nature. 
2. Though the nitric folution of the calculus is not pre- 
cipitated by the oxalic acid, Bergman thinks that lime may 
be found in it in union with fome matter that prevents it from | 
being precipitated; and he finds a proof of this in the afhes 
of burnt urinary calculus, which exhibited the fame pheno- 
mena as lime in his experiments. The nitric folution of cal- 
culus evaporated to drynefs, and burnt or calcined to white- 
nefs, gave him alfo traces of lime. The concentrated ful- 
phuric acid thrown into this folution when evaporated, ex- 
hibited likewife fmall cryftals of the fulphat of lime. This 
earth rarely exceeds ~3, in the urinary calculus. 
3. The concentrated fulphuric acid diffolves the calculus 
with effervefcence by the means of heat; it becomes of a 
blackith brown colour: a little water added to this folution 
makes it immediately, coagulate; a great deal of this liquid 
re-diffolyes the whole coagulum, and forms a folution of a 
yellowifh brown colour. The muriatic acid has no action 
on the urinary calculus, and deprives it of no part of its 
hme, 
4. Berg- 
