Mr. T. Taylor on a new Species of Biliary Calculus, 9 



appearance, I was led to suspect had been incorrectly de- 

 scribed in the manuscript catalogue as consisting of the mixed 

 phosphates. 



This calculus was externally of a dirty white colour, and 

 had the greasy feel of cholesterine calculi ; it floated on 

 water, and when applied to the tongue, left an impression of 

 bitterness. It was of an oval figure slightly flattened, one 

 inch and a half in length, rather better than an inch in thick- 

 ness, and about one inch and a quarter in breadth, but being 

 broken in this direction its exact measurement could not be 

 ascertained. It readily yielded to the knife, and the cut sur- 

 face presented a polished appearance : its structure was la- 

 mellar, being composed of white and reddish-yellow layers 

 arranged concentrically and alternating with each other. The 

 layers were easily separable : at its centre there was a small 

 vacuity. 



When heated before the blowpipe it readily fused, then 

 caught fire, burning with a clear flame and giving out the 

 smell of animal matter, but nothing of a urinous character. 

 It left a carbonaceous residue, which by raising the heat was 

 converted into a white ash. This ash was alkaline, dissolved 

 in water and dilute acetic acid, and the solutions gave a 

 white precipitate with oxalate of ammonia; it was therefore 

 lime. 



When digested in boiling water, the water became slightly 

 brown, but no apparent solution took place : the water on 

 evaporation left a transparent yellowish-brown residue, which 

 had a bitter taste and resembled inspissated bile. 



Boiling alcohol extracted from it only a minute quantity 

 of white fatty matter, which was deposited on cooling. 



A solution of caustic potass removed the whole of the 

 colouring matter, but the rest of the calculus was unacted on : 

 the potass solution was dirty green, and when neutralized 

 with muriatic acid deposited a scanty precipitate of the same 

 tint. 



When digested in nitric acid, effervescence took place, with 

 the escape of a little nitrous acid ; it then melted into a trans- 

 parent oil, which on cooling concreted into a white fatty 

 matter. This substance, when washed with distilled water, 

 melted at a temperature much below that of boiling water. 



When, instead of nitric acid, muriatic or acetic acid was 

 employed, the portion of calculus did not melt until it had 

 been removed from the acid; it then presented similar ap- 

 pearances to that obtained by the action of nitric acid ; con- 

 sequently this white fatty matter was not formed by the action 

 of the nitric acid. 



