Calculus in the Bladder. 77 



the following phDenomena: the nitrates of mercury and of 

 silver. — The muriate ofharvies — the walir (m baivtes — linie- 

 waler — oxalic acid — potash and an\niunia produced no pre- 

 cipitate nor any sensible change. It is clear, therefore, that 

 the distilled water employed contained none of the consti- 

 tuent panicles of this urinary concretion. 



" The dried powder was of the same w eieht as before. 



" 2. I next tieaied this powder with muriatic acid, (the 

 specific gravity of which was 1-1 Si,) keeping the mixture 

 for two days at the temperature of 15' of Reaumur. 1 af- 

 terwards added distilled water. After having filtered the resi- 

 due, when well dried it still weighed 218 grains, and was 

 of a reddish brown colour. 



" 3. The filtered liquor precipitated by lime-water gave 

 a deposit which, when collected and examined, was found 

 to bt pkosp/iate of' lime : it wei^ihed 52 grains. 



" 4. The 243 grains which remained after the second ex- 

 perinient were put into a solution of potash a little diluted, 

 and left for two days at a temperature of 18' of Reaumur. 

 I afterwards filtered ; and the liquor decomposed l)v the 

 acetous acid furnished a precipitate weighing; 230 grains, 

 which, when examined with care, consisltd of 2-26 grains 

 oi uric acid distinctly characterized, and four grains of ani- 

 mal matter. 



" 5. The weight of wliat remained upon the filter was 18 

 grains ; I heated it in a silver crucible until red-hot. Durinc^ 

 this operation, there was a very disagreeable fetid odour 

 discnsiaged, like that of burnt horns or hair. The residue 

 weighed scarcely three grains. 



" 0. These three grains were not dissolved in the sulphuric, 

 the nitric, or muriatic acids, even when heated successively 

 with these acids to ebullition. 



" 7- I then mixed it with four parts of potash, and melt- 

 ed it in a suital^le fire. The whole was dissolved in water^ and 

 I precipitated, by an excess of acid, pure silex. 



*' This substance has only been found twice in the urinary 

 calculi by Messrs. Fuurcrov and Vauquelin, although they 

 have analysed an immensemimberof them. This induced me 

 to rccouiuicnce my labours with the 570 grams which I had 



laid 



