206 



PHYSIOLOGICAL CHEMISTRY 



has been variously estimated at from 500 c.c. to noo c.c. for 24 hours. 

 The specific gravity of the bile varies between i.oio and 1.040, and 

 the freezing-point is about o.56C. As secreted by the liver, the 

 bile is a clear, limpid fluid which contains a relatively low content of 

 solid matter. Such bile would have a specific gravity of approximately 

 i.oio. After it reaches the gall-bladder, however, it becomes mixed 

 with mucous material from the walls of the gall-bladder, and this proc- 

 ess coupled with the continuous absorption of water from the bile has 

 a tendency to concentrate the secretion. Therefore the bile as we find it 

 in the gall-bladder ordinarily possesses a higher specific gravity than 

 that of the freshly secreted fluid. The specific gravity under these 

 conditions may run as high as 1.040. 



The principal constituents of the bile are the salts of the bile acids, 

 bile pigments, neutral fats, lecithin, phosphatides, nucleoprotein, mucin, 

 and cholesterol, besides the salts of iron, copper, calcium, and magnesium. 

 Zinc has also frequently been found in traces. . 



The quantitative composition of bile varies according to the source 

 of the bile, i.e., whether the bile for analysis is obtained from the gall- 



QUANTITATIVE COMPOSITION OF BILE 1 

 (Parts per 1000) 





*For other analyses see Czylharz, Fuchs and v. Fiirth: Bioch. Zeit., 49, 120, 1913. 



2 Hammarsten: Pincussohn's Med.-Chem. Lab. Hilfsbuch, Leipzig, 1912, p. 388. 



'Rosenbloom: Jour. Biol. Chem., 14, 241, 1913. 



4 Includes fatty acids. 



6 Includes cholesterol esters. 



