576 MORBID CONCRETIONS. 



common size, passed by stool. It weighed 147*66 grains, and 

 was as big as a nut. It was soft, had a greasy feel, and gave a 

 yellow powder. Its specific gravity was O912. It had no sen- 

 sible nucleus, and internally consisted of crystalline laminae, hav- 

 ing a yellow colour. It consisted chiefly of cholesterin ; but con- 

 tained a little yellowish -brown matter, which became green when 

 treated with muriatic acid.* 



In 1827, M. Joyeux analyzed two human biliary calculi also 

 emitted by stool. The first was spherical and of the size of a 

 nut. It was lighter than water, and had no sensible smell. It 

 burnt with a lively flame. Its surface was sprinkled with white 

 spots, which, when viewed under a glass, had a soapy appearance. 

 This calculus consisted of two distinct concentric layers : the ex- 

 ternal had a brown colour, and was about a line thick, and was 

 composed of crystalline plates. The second layer was two lines 

 thick, had a deep-brown colour, and its crystalline texture was 

 less apparent. In the centre was a nucleus of six lines in dia- 

 meter. It was lighter coloured than the concentric coats, and 

 was composed of white shining plates. It was composed of, 

 Cholesterin, , 80 



Yellow matter of bile, . 8 

 Carbonate of lime, . 6 



Sulphate of Soda, ~\ 

 Oxide of iron, 6 



Bile, . ) 



100 

 The concentric layers were composed of, 



Cholesterin, . 76 



Yellow matter, . 20 



Bile, . ' 1 4 



Sulphate of soda and loss, / 



100 

 The nucleus was composed of, 



Cholesterin, . 84 



Yellow matter, . 12 



Bile, . I 4 



Sulphate of soda and loss, / 



lOOf 

 * Jour, de Pharm. vi. 215. f Ibid. xiii. 550. 



