94 INTESTINAL, PROSTATIC, AND UEINARY CALCULI. 



are the reactions of calculi with prevalence of car- 

 bonate of lime. 



Calculi, intestinal. From horses fed upon bran. 

 Saw the calculus in two halves, and observe nucleus. 

 Examine saw-meal or a chip of the hard crystalline 

 matter. It loses water and ammonia by heating to 

 redness, and leaves a residue easily soluble in hydro- 

 chloric acid, and reprecipitated, on standing in crystals, 

 by excess of ammonia. . The calculus, therefore, consists 

 mainly of ammonio-phosphate of magnesium, with which 

 more or less phosphate of calcium is mixed. It hardly 

 contains any inorganic matter. 



Calculi, prostatic. Minute concretions, from the 

 size of mustard or hemp seeds to that of barley- 

 corns. Dissolve powder in acetic acid, and observe 

 evolution of carbonic acid gas. Add to solution 

 excess of ammonia, and observe that solution remains 

 clear ; absence of phosphates of earths ; if solution 

 forms deposit phosphates of earths are present. If 

 necessary filter, and add oxalate of ammonium; a 

 copious precipitate of calcium oxalate will ensue. The 

 calculi, therefore, consist principally or entirely of 

 carbonate of calcium. 



Calculi, urinary* Systematic analysis. Powder the 

 calculus. Heat a small portion of the powder to 

 redness on some platinum foil and observe whether 

 any residue is left which will not burn off. 



A. In case it leaves a fixed residue, take a small 



