SECRETION OF BILE. 



319 



Analysis of Human Bile. Water, from 82 to 90 per cent., salts of the biliary 

 acids, from 6 to n per cent., fats and soaps, 2 per cent.; cholesterin, 0.4 per cent.; 

 lecithin, 0.5 per cent.; mucin, from i to 3 per cent.; ash, 0.6 per cent. The 

 amount of sulphur contained in dry bile from a dog is from 2.8 to 3.1 per cent.; the 

 amount of nitrogen, from 7 to 10 per cent. The sulphur of the bile is not oxidized 

 into sulphuric acid, but it appears in sulphur-containing compounds in the urine. 



SECRETION OF BILE. 



The secretion of bile is not a simple nitration of already prepared 

 materials from the blood through the liver, but a chemical production, 

 attended with oxidation, of the characteristic biliary matters in the 

 liver-cells, which exhibit histological change during the process of diges- 

 tion, and to which the blood of the gland only supplies the raw material. 

 It takes place continuously, the bile being in part temporarily stored 

 in the gall-bladder, and only discharged in considerable amount at the 

 time of digestion. The higher temperature of the blood in the hepatic 

 veins, as well as the large amount of carbon dioxid in the bile, indicates 

 the occurrence of oxidation-processes in the liver. Even the water of 

 the bile is not simply filtered out, since the pressure in the biliary pas- 

 sages may exceed that in the portal vein. It appears that the bile is 

 derived from proteid only, and that the excretion of carbon dioxid in 

 the act of respiration bears a certain relation to its production. In 

 animals (birds) deprived of their livers the constituents of the bile are 

 not produced. 



After an albuminous diet the liver-cells undergo increase in size, and in still 

 greater degree after administration of carbohydrates, in connection with which 

 they contain glycogen ; while after ingestion of fat they likewise become larger and 

 contain fatty granules, principally at the periphery of the liver-lobules. Irritation 

 of the celiac plexus causes reduction in the size of the cells, with deficiency in 

 glycogen, and it appears to spur them on to secretion. 



The experiments of Kallmeyer and Jul. Klein, performed under the direction 

 of Alex. Schmidt, have yielded the interesting result that a paste of fresh, "sur- 

 viving" liver-cells produces the glycin and the taurin of the biliary acids from 

 a mixture of hemoglobin (or serum) and glycogen (or dextrose) and that addition 

 of soda or 0.6 per cent, sodium-chlorid solution favors this production. In addition 

 to this production, a body resembling urea is formed. It is now established that 

 the source of the latter is to be referred to the liver. 



Anthen, under Alex. Schmidt's direction, found that ''surviving" liver-cells 

 possess the ability to take up dissolved hemoglobin in their cell-bodies, and, in 

 the presence of glycogen, to transform this into a pigment closely related to the 

 biliary coloring-matter. 



The Amount of Bile. Copemann and Winston found the amount of 

 bile to be from 700 to 800 cu. cm. in twenty-four hours, in a small woman 

 with a biliary fistula, in whom the common bile-duct was completely 

 closed, so that no bile could flow into the intestine; Mayo Robson found 

 the amount to be 862 cu. cm. in a similar case; Paton found it to be as 

 much as 680 grams, with 2.2 per cent, solid matter. 



Older estimates are: 533 cu. cm. by v. !Wittich ; from 453 to 566 grams 

 by Westphalen; 652 cu. cm. by Ranke, in 24 hours. Analogous estimates for 

 animals are, to one kilogram of dog 32 grams (1.2 per cent, solid matter) 

 one kilogram of rabbit 137 grams (2.5 per cent, solid matter); t 

 of guinea-pig 176 grams (5.2 per cent, solids). 



The flow of bile into the intestine exhibits two maxima during a 

 digestive period, one from the second to the fifth, and the other from 

 the thirteenth to the fifteenth hour after the meal. The cause resides 

 in reflex stimulation of the hepatic vessels, which in consequence become 

 greatly distended with blood. 



