568 MORBID CONCRETIONS. 



lindrical shape, tapering towards the extremities. It was com- 

 posed of concentric coats adhering very slightly to each other. 

 It was composed of silica mixed with a small quantity of per- 

 oxide of iron and some animal matter.* 



4. The Hog. Fourcroy found the calculus from a hog, ex- 

 amined by him and Vauquelin, to consist almost entirely of car- 

 bonate of lime. And a urinary calculus from a hog analyzed 

 by Mr Brande, contained 90 per cent, of carbonate of lime, and 

 the rest was animal matter.f In the year 1811, I analyzed a 

 calculus from the urethra of a hog, which I got from Mr Col- 

 ville, surgeon in Ayton, Berwickshire. It was nearly spherical, 

 weighed 44*2 grains, and had a specific gravity of 1 '5 95. It was 

 white, had a silky lustre, and was composed of a congeries of 

 very small needles. It consisted entirely of phosphate of lime 

 and animal matter.J In 1825, a calculus from the bladder of a 

 hog was analyzed by M. Caventou, who found its constituents 

 to be, 



Ammonia-phosphate of magnesia, 9 9 '5 

 Animal matter, . . 0-4 



99-9 



In the Hunterian collection of calculi in the Glasgow Universi- 

 ty museum there is a small phial containing a number of dark- 

 coloured pearls, labelled as extracted from the bladder of a hog. 

 They consist of alternate layers of carbonate of lime and animal 

 matter. 



From these facts it appears that the urinary calculi of hogs, so 

 far as they have been examined, consist sometimes of carbonate 

 of lime, sometimes of phosphate of lime, and sometimes of am- 

 monia-phosphate of magnesia. 



5. The Dog. Fourcroy and Vauquelin examined several cal- 

 culi from the bladder of the dog, and found them similar to the 

 human mulberry calculi. || Mr Brande in 1808 analyzed a large 

 calculus from the bladder of a dog twenty years of age. It 

 weighed sixteen ounces, was extremely hard, and of a gray co- 

 lour. When cut through it exhibited a nucleus about the size 

 of a hazel-nut, partly made up of concentric layers of phosphate 



* Ann. de Chim, et de Phys. xliv. p. 420. f Phil. Trans. 1808, p. 236. 

 | Annals of Philosophy, ii. p. 59. Jour, de Pharmacie, xi. p. 465. 



|| Ann. de Mus. d'Hist. Nat, iv.p. 338. 



4 



