THE BILE. 539 



In dogs, with artificial biliary fistulas, the quantity secreted daily is 

 about J oz. to every pound weight of the animal, or g^d part of its 

 weight (Kolliker, H. Muller). Supposing the weight of a man to be 

 140 Ibs., this would give 70 oz. or 4 Ibs. 6 oz. avoirdupois in a day, 

 of which about ^gth, or nearly 3 oz., would be solid matter. This 

 estimate, however, appears very high. Bidder and Schmidt calculate 

 the daily quantity secreted by a man to be 56 oz. ; Nasse and Platner's 

 observation on the dog, would give a total daily quantity for man of 

 33 J oz. ; whilst others again have estimated it at only from 17 to 24 

 oz. The specific gravity of the cystic bile in man, varies from 1026 

 to 1032: that of hepatic bile is of course less. The cystic bile of man 

 contains about 10 per cent, of solid matter; while the bile from an 

 artificial fistula in the bile duct of an animal, i. e., hepatic bile, contains 

 from 3 to 5 per cent. only. 



The analysis of cystic ox gall by Berzelius, gives the following per- 

 centage composition: 



Water, 90.44 



Bilin, with fat and coloring matters, . . . 8. ] 



Mucus, chiefly cystic, 3 i 9.56 



Salts, . 1.26 J 



100.00 



The analyses by other chemists show a similar composition, but, 

 according to Strecker, the bilin of Berzelius is a compound substance. 

 Its two characteristic constituents are the colorless conjugated fatty 

 acids, named glycoeholic or cholic, and taurocholic; the one formed by 

 the combination of a nitrogenous body, named gtycocin, or glycocoll 

 and ckolalic acid ; the other, formed by the union of the same acid with 

 another nitrogenous body, which contains sulphur, named taurin. 

 The chemical relations of these substances may be seen by comparing 

 their atomic compositions (p. 85). 



Cholalic acid crystallizes in white tetrahedra; dissolved in sulphuric 

 acid, with the addition of sugar, it yields a purple violet color, the re- 

 action of the so-called Pettenkofer's test for bile. Glycocoll, obtain- 

 able also by the action of acids or alkalies upon glue and some other 

 animal substances, forms hard, transparent, colorless crystals, soluble 

 in water, but nearly insoluble in alcohol and ether. Taurin crystal- 

 lizes in white hexagonal prisms, inodorous and almost tasteless; it 

 contains the large proportion of one-fourth its weight of sulphur; it 

 leaves much sulphurous acid on being burnt, and gives off sulphuretted 

 hydrogen when decomposed. Both glycocoll and taurin are neutral 

 substances having a tendency to unite with acids, to form, as in the 

 bile, conjugated acids. Glycoeholic, or cholic acid, consists of fine 

 crystalline needles, soluble in water and alcohol, but very slightly so 

 in ether, having a bitter sweet taste, and a strong acid reaction. Tau- 

 rocholic acid has not yet been obtained in a crystalline form. In the 

 bile, the glycoeholic and taurocholic acids, which form from 4 to 7 per 

 cent, of that secretion, are always united with soda, as glycocholate 

 and taurocholate of soda. The bile, however, occasionally contains an 



