On some New Species of Animal Concretions. 37 



concentric layers of a dirty white colour with a shade of pink. 

 They were of an ovoid figure, but all of them were remark- 

 able for being flattened in a peculiar manner on one side. 



When heated before the blowpipe they consumed like a 

 uric acid calculus, but left a fusible salt which spread over the 

 platina foil, and tinged the outer flame violet. When heated 

 in a test-tube, carbonate and hydrocyanate of ammonia with 

 a little empyreumatic oil and water were given off'. The car- 

 bonaceous residue, when treated with water, gave a solution 

 which had a strong alkaline reaction, effervesced with acids, 

 and emitted a slight odour of prussic acid. Tartaric acid and 

 chloride of platina produced in the solution precipitates indi- 

 cative of the presence of potass. 



Water digested upon the powdered calculus afforded a so- 

 lution which deposited small scales of suburate of potass upon 

 being evaporated ; the liquor gave no precipitate with a salt 

 of lime, consequently no soluble oxalate was present. 



When digested with caustic potass, ammonia was freely 

 evolved, and the whole dissolved with the exception of a little 

 flocculent matter. The alkaline solution, when mixed with 

 muriatic acid, gave a copious precipitate of uric acid. It was 

 therefore evident that these concretions consisted chiefly of 

 urate of potass mixed with urate of ammonia. 



The relative proportion of their constituents was estimated 

 in the following manner : — 



19'lOgrs., when submitted to a current of dry air at 212° 

 Fahr., lost 0*32 water, = 1*67 per cent. The dried powder 

 was digested in boiling acetic acid, which decomposed the 

 urate of potass and left a residue which weighed 15*02grs., 

 = 78*64 per cent. This residue was found to consist of uric 

 acid, containing a small trace of oxalate of lime. 



The acetic solution being evaporated to dryness was boiled 

 with proof spirit; the whole dissolved with the exception of 

 some light yellow flocks of animal matter, which amounted to 

 0*52 gr.j = 2*73 per cent. 



The spirituous solution being evaporated to dryness, the 

 earthy and alkaline acetates it had contained were decom- 

 posed by the addition of muriatic acid ; the mixture was evapo- 

 rated to dryness and heated red-hot in a platina crucible. The 

 residue dissolved entirely in water, with the exception of 0*06 

 gr. of phosphate of lime. The aqueous solution was mixed 

 with carbonate of ammonia, a precipitate fell, which when 

 dried and ignited was equivalent to 0*36 gr. of pure lime. It 

 contained however a trace of phosphate of lime. 



The solution from which the above precipitates had been 

 separated was evaporated to dryness and the residue heated 



