THE BILE. 331 



the biliary matter, consisting of bilin and the products 

 of its spontaneous decomposition yields, on analysis, 76 

 atoms of carbon, 66 of hydrogen, 22 of oxygen, 2 of 

 nitrogen, and a certain quantity of sulphur.* Comparing 

 this with the ultimate composition of the organic parts of 

 blood which may be stated at C 48 H 36 N 6 14 with sulphur 

 and phosphorus it is evident that bile contains a large 

 preponderance of carbon and hydrogen, and a deficiency 

 of nitrogen. The import of this will presently appear. 



The process of secreting lile is probably continually going 

 on, but appears to be retarded during fasting, and ac- 

 celerated on taking food. This was shown by Blondlot 

 who, having tied the common bile-duct of a dog, and 

 established a fistulous opening between the skin and gall- 

 bladder, whereby all the bile secreted was discharged at 

 the surface, noticed that when the animal was fasting, 

 sometimes not a drop of bile was discharged for several 

 hours ; but that, in about ten minutes after the introduc- 

 tion of food into the stomach, the bile began to flow 

 abundantly, and continued to do so during the whole 

 period of digestion. Bidder and Schmidt's observations 

 are quite in accordance with this. 



The bile is probably formed first in the hepatic cells ; 

 then, being discharged into the minute hepatic ducts, it 

 passes into the larger trunks, and from the main hepatic 

 duct may be carried at once into the duodenum. But, 

 probably, this happens only while digestion is going on ; 

 during fasting it flows from the common bile-duct into 

 the cystic duct, and thence into the gall-bladder, where it 

 accumulates till, in the next period of digestion, it is dis- 

 charged into the intestine. The gall-bladder thus fulfils 



* The sulphur is combined with the taurin one of the substances 

 yielded by the decomposition of bilin. According to Dr. Kemp, the 

 sulphur in the bile of the ox, dried and freed from mucus, colouring 

 matter, and salts, constitutes about 3 per cent. 



