CH. XI.] THE PROTEINS OF BILE. 269 



in strong acetic acid. (See Ex. 3 1 7.) In human bile, how- 

 ever, mucin is present as well as nucleoprotein. 



The protein is secreted by the cells lining the ducts 

 and the gall bladder, so that bile from the gall bladder 

 contains a much greater percentage than fistula bile. 



320. To a small quantity of undiluted bile add strong acetic 

 acid, drop by drop. A precipitate is formed, insoluble in excess of 

 acid. This precipitate consists of a nucleoprotein, together with a 

 considerable amount of the bile salts and bile pigments. 



