On Cystic Oxide, a new Species of Urinary Calculus. 51 
botanist, all the time necessary to his inquiries is allowed : 
the zoologist may consult anatomy and physiology at his 
leisure; he can observe the habits of animals: the gardener 
must not wait the time of inflorescence to distinguish plants : 
the butcher should know an ox or an ewe without being 
obliged to ascertain if they could reproduce beings fecund and 
similar to themselves: in like manner the miner ought not 
to stop at particulars: but I do not see why, among all 
those who study nature, the mineralogist should be the~ 
only one condemned to live in a perpetual hurry. 
[fo be continued. ] 
VIIT. On Cystic Oxide, a new Species of Urinary Calculus. 
By Wiriram Hype Wottaston, M.D. Sec.R.S.* 
Tue principal design of the present essay is to make 
known the existence, and to describe the leading properties, 
of a new species of urinary calculus from the human blad- 
der; but I shall at the same time take the opportunity of 
correcting an inaccuracy or two that I have observed in my 
former communication on this subject. (Phil. Trans. 1797.) 
Ton that occasion took notice of five kinds of urinary 
ealcull, 
1. The lithic acid, since called uric acid, originally ana- 
lysed by Scheele. 
2. The oxalate of lime, or mulberry calculus. 
3. The phosphate of lime, or bone-earth calculus. 
4. The ammoniacal phosphate of magnesia. 
5. The fusible calculus, which consists of the two last 
species combined. 
Tt is now about five years since I first met with another 
species, evidently differing from each of those before de- 
scribed. It was in the possession of Dr. Reeve of Norwich, 
who obligingly yave me a portion of it for the purpose of 
examining its chemical qualities. It had been taken from 
his brotber when he was five years old, and at that time was 
covered with a coating of phosphate of lime very loose in 
its texture, and consequently very soon separatedf. This 
species is probably very rare ; for, although I have omitted 
* From Philosophical ‘Transactions for 1810, Part II. . 
4+ 1am informed, that another stone formed afterwards in the bladder of 
this boy, and that he dicd in consequence, without submitting to the opera- 
tion a second time. ‘The stone found in his bladder after death, consisted 
rincipally of uric acid, but was peculiar in one respect, as its centre was 
Satins by the removal of some more soluble substance, of which the nucleus 
had consisted. 
D2 . - no 
