140. = On the Compofition of Urinary Concretions. 
“The fpecimen marked No. 8. in the fame colleétion, 
which was faid to be a vefical calculus of a horfe, appeared 
to confift of the three ingredients juft mentioned. 
T have met with two inftances of a depofit of a prodigious 
quantity of matter in the urinary bladder of horles, which 
had not cryftallized, or even concreted: it amounted, in 
one fpecimen, which was given to me by Dr. Marfhall, to 
feveral pounds weight; and in the other, which is in the 
poffeffion of Mr. Home, to about 45 pounds. Its compofi - 
tion was, principally, carbonate of lime and common animal 
matter *, 
I have not found any inftance of human urinary calculi of 
a fimilar compofition to that of the rabbit, and thofe of 
horfes above defcribed, which confift of carbonate of lime 
and animal matter; and I believe that human urinary 
calculi very rarely occur of a fimilar compofition to thofe of 
the dog and horfes above mentioned, which were found to 
confift of phofphate of ammoniac, phofphate of lime, and 
animal matter, without containing wric oxide. 
The difference in the conftitution of urinary concretions 
may depend on. the difference of the urinary organs of dif- 
ferent animals, on the food and drink +, and on the various 
difeafed and healthy ftates of the urinary organs. 
. T have not found the uric oxide in the urinary concretions 
of any phytivorous animal; but, whether it would be formed 
in the human animal when nourithed merely by vegetable 
matter, muft be determined by future obfervations. In the 
mean time, it is warrantable to conclude, from analogy, 
that it would not, and the application of this fact to practice 
~ ® Since this paper was read, Mr. Blizard has “been fo. attentive as te 
fend me another f{pecimen of the fame kind of depofit as thofe here 
mentioned. It now appears probable, that fuch depofits frequently take 
place, although I believe they have not been noticed before. 
“4 I found the ftomach-concretion called oricntal bexoar, to confit 
merely of vegetable matter; as did the inteflinal coucretion of a theep, 
is 
