BIIJS 71 



lecithin, urea, and mineral salts, of which sodium chloride and the 

 phosphates of iron, calcium, and magnesium are the most important. 



Bile is a yellowish, reddish-brown, or green fluid, according to 

 the relative preponderance of its two chief pigments. It has a musk- 

 like odour, a bitter-sweet taste, and a neutral or faintly alkaline re- 

 action. 



The specific gravity of human bile from the gall bladder is 1026 to 

 1032 ; that from a fistula, 1010 to 1011. The greater concentration 

 of gall-bladder bile is partly but not wholly explained by the addition 

 to it from the walls of that cavity of the mucinoid material. 



The amoimt of solids in bladder bile varies from 9 to 14 per cent., 

 in fistula bile from 1"5 to 3 per cent. The following table shows that 

 this low percentage of solids is almost entirely due to want of bile salts. 

 This can be accounted for in the way first suggested by Schiff — that 

 there is normally a bile circulation going on in the body ; a large 

 uantity of the bile salts that passes into the intestine is first spht 

 up, then reabsorbed and again secreted. Such a circulation would 

 obviously be impossible in cases where all the bile is discharged to the 

 exterior. 



The following table gives some important analyses of human 

 bile :— 



Bile Mucin. — There has been considerable diversity of opinion as 

 to whether bile mucin is really mucin. The most recent work in 

 Hammarsten's laboratory shows that differences occur in different 

 animals. Thus in the ox there is very httle true mucin, but a great 

 amount of nucleo-proteid ; in human bUe, on the other hand, there is 

 very httle if any nucleo-proteid : the mucinoid material present there 

 is really mucin. (On the general characters of Mucin and Nucleo- 

 Pboteids see pp. 28 and 29.) 



