of Urinary Coneretions. | ‘135 
really from the urinary bladder of a dog. It is worthy to be 
noticed, that the animal appeared to be in perfect health. ” 
This concretion is of an oval figure; is three inches and 
three quarters in length, and three inches in breadth; is 
white as chalk; its furface is rough and uneven. Being 
fawed through longitudinally, no nucleus was found, nor 
was it laminated, but near the centre it was radiated, and 
contained fhining /picula. In other parts it was, for the 
moft part, compact and uniform in its texture. It weighed | 
nearly ten ounces and a half. Its fpecific gravity was found 
to be greater than that of human urinary concretions, in 
general; which I have learned by experiments is alfo the 
cafe with urinary and inteftinal concretions of other brute 
animals, efpecially with thofe of the horfe. 
The fpecific gravity of the prefent calculus was 1,7. 
That of one from the urinary bladder of the human fub- 
ject, of the fort called mulberry calculus, and which con- 
fitted almoft entirely of uric oxide, was 1,609. 
That of another human urinary coneretion, of the fame 
compofition as the former, but quite {mooth, extracted by 
Mr. Ford, was 1,571. 
1. The prefent calculus of the dog had no tafte, nor {mell, 
till expofed to fire. 
2, Under the blowpipe it firft became black, and emitted 
the fmell of common animal matter; it next {melt ftrongly of 
empyreumatic liquor cornu cervi; and, after burning fome 
time, became inodorous, and white, and readily melted, like 
fuperphofphate of lime. 
3, On trituration with lye of cauftic foda, there was a co- 
pious difcharge of ammoniac, . 
4. It diffolved, on boiling in nitric acid: the folution was 
clear and colourlefs; and, on evaporation to drynefs, left a 
refidue of white bitter matter, which, under the blowpipe, 
emitted, weakly, the fmell of animal matter. 
5. Upon diftilling a mixture of 150 grains of this concre~ 
tion pulverized and two pints and a half of pure water, to 
hy. Bea three 
%, 
