370 



CHEMISTRY OF THE DIGESTIVE PROCESSES. 



percentage of total solids and a correspondingly low specific gravity 

 (1010). In the gall bladder absorption of water takes place, 1 and a 

 mucin-like substance secreted by the epithelium of the gall bladder is 

 added to it, so that it becomes viscid in consistency, the percentage of 

 total solids is much increased, and the specific gravity rises (1030 to 1040). 



According to the time it stands in the gall bladder, these changes 

 become more or less advanced, which accounts for much of the variation 

 observed in the quantitative composition of different specimens of bile. 



The following table of analyses of dogs' bile, (a) from the gall bladder 

 and (b) freshly secreted from a fistula, illustrates this difference : 2 



Bile is an alkaline fluid containing on an average 0*2 per 1000 each of 

 sodium carbonate and alkaline sodium phosphate. It has an intensely 

 bitter taste, leaving a sweetish after-taste in the case of human or ox 

 bile, but not in that of rabbit's or pig's bile. The bile of the ox and 

 some other animals has a faint characteristic odour resembling musk, 

 especially after warming. The colour is very variable : in carnivora it 

 is usually golden-yellow ; in herbivora a grass -green ; but these colours 

 are not constant, and vary with the amount of oxidation of the bile 

 pigments ; the two chief colours are often mixed with brown, giving 

 intermediate shades of yellowish and greenish brown. Human bile, 

 when observed in a healthy condition and immediately after death, is 

 often green, occasionally golden-yellow in colour. 



Bile contains no coagulable proteid, and remains clear on boiling ; it 

 can also be diluted with water without any turbidity arising. In human 

 bile true mucin is present, 3 but the substance which gives viscidity to ox 



1 Accompanied by a selective absorption of inorganic constituents, so that the percentage 

 of chlorides in gall bladder bile is even less than that in liver bile (Hammarsten, loc. cit., 

 sub. 15). 



2 Hoppe-Seyler, " Lehrbuch der Physiol. Chem.," Berlin, 1881, S. 302. See also 

 Hammarsten, Nova Acta. Reg. Soc. Sc. Upsala, 1893, .Ser. 3, vol. xvi. ; Jahresb. u. d. 

 Fortschr. d. Thier-Chem. , Wiesbaden, 1893, Bd. xxiii. S. 331. 



3 Hammarsten, Nova Acta Reg. Soc. Sc. Upsala, 1893, Ser. 3, vol. xvi. ; Jahresb. ii. d. 

 Fortschr. d. Thier-Chem., Wiesbaden, 1893, Bd. xxiii. S. 333. 



