SS4 



NEW SPECIES O? URINARY CALCULUS. 



Solrents. 

 Acid. 



Alkaline. 



Precipitates 

 isom acids 



aid alkalis. 



The solvents on the contrary, are far more numerous. It 

 is dissolved, in considerable quantity, by muriatic acid, by 

 nitric acid, by sulphuric acid, by phosphoric acid, and by 

 oxalic acid. 



It is also dissolved readily by pure alkaline menstrua : by 

 potash, by soda, by ammonia, and by lime water. It is 

 even dissolved by fully saturated carbonates of potash or of 

 soda. Accordingly, these alkalis are not so convenient for 

 the precipitation of this matter from acid solutions, as the 

 carbonate of ammonia, which is not capable of redissolving 

 the precipitate, though added in excess. 



For a similar reason, the acids best suited for its preci- 

 pitation from alkaline solutions, are the acetic and citric 

 acids. But the tartaric acid may occasion an appearance 

 of precipitation, by forming a supertartrate with the alkali 

 employed. 

 Forms crystals The combination of this substance with acids may be 

 witk acids, made to crystallize without difficulty ; and they form slen- 

 der spicula radiating from the centre, which readily dis- 

 solve again in water, unless they have been injured by being 

 in any degree overheated. 



The muriatic salt is decomposed by the heat of boiling 

 water, on account of the volatility of the acid, and the rest 

 • are easily destroyed by a greater excess of heat. 



The salt formed by combination with nitric acid does 

 not yield oxalic acid, and does not become red, as the uric 

 acid does, when similarly treated ; but it turns brown, be- 

 coming gradually darker, till it is ultimately black. 



When the combinations with alkalis are evaporated, they ^ 

 leave small granular crystals ; but as I was desirous of ren- 

 dering my experiments as numerous as a limited quantity 

 would permit, the portion which I could employ in any one 

 experiment was too small for nie to attempt to determine 

 the form of such crystals. 



When a hot solution in potash was neutralized by distilled 



vinegar, the precipitate did not immediately take place, 



but formed gradually during the cooling of the liquor in 



minute crystals, some at the surface of the fluid, and others 



. _ . ^ attached to the sides of the vessel. The only definite form, 



aal crystals', which I could observe, was that of flat hexagonal plates; 



but 



aad with alka 

 lis. 



Precipitated 

 from potash 

 by vinegar 



