5 6 ° 
MECHANISM OF BILE SECRETION. 
of fluid, about 70 c.c. per diem, is continually secreted from the walls of 
the gall bladder. 1 How far this fluid is a physiological secretion, and 
how far it is due to pathological conditions, is difficult to decide. 
That water is secreted by the liver cells, as well as by the cells of 
the ducts, is proved by the way in which pigments, 2 which are secreted 
by the liver cells alone, are washed down into the bile passages. 
The elimination of the water of the bile is a process of secretion, 
and not of transudation. Heidenhain's observations on the relative 
pressures in the bile passages and in the blood vessels passing to the 
liver, 3 given in the following table, demonstrate very clearly that, though 
the pressure of secretion of bile is low, it is nevertheless considerably 
higher than the blood pressure in the portal vein. 
No. 
Bile Pressure. 
Pressure in Vena Mesenterica 
Superior. 
1 
2 
3 
4 
5 
220 mm. carbonate of soda sol. 
175 ,, 
204 ,, 
no ,, 
180 „ 
90 mm. carbonate of soda sol. 
67 „ 
90 „ 
50 ,, 
65 ,, 
The absorption of water from the alimentary canal seems under 
certain conditions to increase the secretion of water by the liver. 
Eohrig, 4 Bidder and Schmidt, 5 and Zalesky, 6 noticed that the intro- 
duction of water into the stomach and intestine of dogs with biliary 
fistulye increased the flow of bile. Kosenberg 7 found that if the intestine 
had previously been cleared out by a glycerin enema, the introduction 
of 500 c.c, of water into the intestine increased the flow of bile. In a 
case of complete biliary fistula in a woman, 8 the amount of the bile 
secretion was greater upon the days on which a large quantity of fluid 
was taken, and this increase was in the water of the bile, not in the 
solids. 
Inorganic salts. — The analyses of the bile of the dog given by 
Hoppe-Seyler, 9 show that in bile taken from the gall bladder the salts 
constitute about 5 per cent, of the solids, while in freshly secreted bile 
they amount to about 13 or 14 per cent. The freshly secreted bile 
alone need be considered in discussing the mode of formation of these 
salts. A comparison of the salts of the bile with the salts of the blood 
plasma indicates that the percentage amount of salts is smaller in bile 
than in blood, and that, while chloride of sodium is the most abundant in 
1 Birch and Spong, Journ. Physiol., Cambridge and London, vol. viii. p. 378 ; Mayo 
Robson, Proc. Roy. Soc. London, 1890, vol. xlvii. p. 499. 
- Wertheimer, Arch, dephysiol. norm, etpath., Paris, 1891, p. 724. 
3 Hermann's "Handbnch," Bd. v. S. 269. 
* Med. Jahrb., Wien, 1873, Bd. ii. 
5 "Die Verdauungssafte," 1852, S. 166. 
Hofmann and Schwalbe, Jahrcsb. ii. d. Fortschr. d. Anat. u. Physiol., Leipzig. 1877, 
S. 219. 
7 Arch. f. d. ges. Physiol., Bonn, 1890, Bd. xlvi. S. 361. 
8 Noel Paton and Balfour, Rep. Lab. Roy. Coll. Phys., Edin., 1891, vol. iii. p. 191. 
9 "Pbysiol. Chem.,"S. 302. 
