BILE. 19 



and very probably also cholanic and fellanic acids are produced. 

 The biliary secretion, as it exists in the liver, may be regarded 

 as pure bilin mixed with biliverdin and fats ; the bilin probably 

 commences its metamorphoses in the gall-bladder, and conti- 

 nues them in its passage onwards into the intestinal canal. If 

 fellinic and cholinic acids are formed in the gall-bladder, then 

 the presence of the two bilifellinic acids in fresh bile may be at 

 once assumed, since they are only to be regarded as combina- 

 tions of the former with different proportions of bilin. It is 

 not by any means probable that cholic acid exists in fresh bile, 

 and the presence of dyslysin and taurin may be positively 

 denied ; consequently, the biliary resin, the mixture of fellinic 

 and cholinic acids and dyslysin does not pre-exist in the bile. 



Berzelius and Thenard have made quantitative analyses of 

 healthy human bile : they found, in 1000 parts : 



Berzelius. Thenard. 



Water . . . 907-4 Water . . . 909-0 



Bilin, fellinic acid, &c. . 80-0 Yellow and very bitter resin 37*3 



Mucus dissolved in a free alkali 3'0 Brown pigment and mucus 1-8 9'0 



Free alkali and the ordinary salts 9'6 Albumen . . 38-2 



Soda holding the resin in 



solution . . 5-1 

 Salts of potash and soda, and 



peroxide of iron . 4-1 



According to Gmelin and Tiedemann, human bile contains 

 biliary sugar, brown pigment, a little biliary resin, cholesterin, 

 ptyalin, mucus, oleic acid, and salts. 



[In the year 1837, Dema^ay announced that the bile con- 

 sisted essentially of an organic acid combined with soda. He 

 termed this acid choleic, and obtained it in the following man- 

 ner : Bile from which the mucus had been precipitated by 

 alcohol was evaporated on the water-bath, and ten parts of the 

 dried residue were dissolved in 100 of water, to which ten of 

 hydrochloric acid had been added. Allowing evaporation at a 

 moderate temperature to proceed, it was observed that a dark 

 green oil collected on the surface, while, at the same time, the 

 fluid became turbid. On removing the oil, and allowing the fluid 

 to rest for some time, it gradually became clear, with the precipi- 

 tation of a green deposit. This dark green bitter precipitate is 



