

ON THE STRUCTURE OF CALCULf. 43 



The deposition of calculous matter upon the bougie was 

 covered with blood, and in very small quantity, the bougie 

 having been removed by an operation soon after it bad 

 passed into the bladder. It appeared to consist chiefly of 

 -phosphate of lime. 



The incrustation upon the hazel nut was also destitute pf 

 uric acid. 



Sect. TV. Of the Calculi of the Urethra, 



All those that were examined had escaped from the blad- Calculi of the 

 der while very small, and had afterward lodged in the mem- 

 jbranous part of the urethra, where they had increased in 

 size, and formed a cavity, in which they were more or less 

 imbedded. 



Two of these calculi were broken. 



The fragments consisted in one instance of ammoniaeo- 

 rnagnesian phosphate, and phosphate of lime, with a small 

 portion of uric acid: and in the other the fragments were 

 composed entirely of the ammoniaco-magnesian phosphate? 



The third calculus was of a very remarkable appearance; 

 its form being that of a perfect sphere, about half an inch 

 in diameter. It was coated with small but very regular 

 crystals of the triple phosphate in its purest state. On ac- 

 count of the singularity of the form and external appear- 

 ance of this calculus, it was not sawn through; the nucleus, 

 in all probability, is a small kidney calculus, which lodging 

 in the urethra has become coated with triple phosphate. 



Sect. V. Analysis of Calculi from other Animals. 



J. The horse. Calculi of the 



A. From the kidney. horse. 



A very large calculus, from the kidney of a horse, was From the kid- 

 pomposed of ne Y* 



Phosphate of lime » 76 



Carbonate of lime ................ 22 



98- 



B. From the bladder* 



This calculus was also of a large size; its weight, when From the Mad- 

 perfectly dry, nine ounces and a half; its external surface der * 



very 



