on the Composition of Urinary Concretions . 43 
smell; and, urged with the intensest fire, showed no signs of 
fusibility. 
2. It readily dissolved, with effervescence, like marble, in 
both muriatic and nitric acids, giving clear solutions. 
3. The nitric solution (2.) being evaporated partly to dry- 
ness, and partly to the consistence of extract, the dry residuary 
matter was white; and the extract-like matter, which was bitter, 
could not be fused under the blowpipe; but, when brought to 
the state of a powder, the particles of it were made to cohere 
loosely together into one mass. 
4. On dropping sulphuric acid into the muriatic solution, (2.) 
turbidness, and a copious white precipitation, immediately en- 
sued, from the composition of sulphate of lime. 
From these experiments it is warrantable to conclude, that 
the above urinary calculus of a rabbit consisted principally of 
* carbonate of lime and common animal matter, with, perhaps, 
a very small proportion of phosphoric acid : it certainly con- 
tained no uric oxide. 
I examined, in the same mafmer, a concretion which was 
said to be from the stomach of a monkey; but I have not evi- 
dence of its origin equally satisfactory as that of the two last 
calculi. Its composition was found to be similar to that of the 
calculus of the rabbit, viz. carbonate of lime and animal matter. 
Its obvious properties were also the same; it was of the size 
of the largest nutmeg. 
III. On urinary Concretions of the Horse . 
I examined several specimens in cabinets, said to be vesical 
calculi of the horse, and found none of them to contain the 
uric oxide above described; but that they consisted (as well 
G 2 
