314 
A. H. LOGAN. 
The mucin is obtained from the mucus glands in the ducts, j 
It passes unchanged into the intestines, and is evacuated with 
the f se c e s 
The bile pigments are sometimes of a reddish form— 
bilirubin, and are probably obtained from the haemoglobin ol j 
the red corpuscles in the liver, as it is identical with the hxmato- j 
iden of old blood clots. On oxidation they become green— 
biliderdin. On entering the intestines, the biliderdin is de¬ 
composed by taking up water, forming hydro-biliderdin, 
and is thus eliminated as the coloring matter of the faeces— • 
stercobilin. . , 
The bile acids are two compound acids, glycocholic, and 
taurocholic, which exist in combination with sodium. 1 hey 
are formed in the liver, as no trace of them can be found m 
the blood. The bile salts in digestion are split up, decompos- ; 
imr the glycocholic and taurocholic acids. The cholic acid 
remaining free in the intestines is eliminated with the fmces, 
while the glycin and taurin are reabsorbed into the blood. . 
The principal fatty matters of the bile are lecithin, palmitm, ; 
stearin, olein, and soda soaps. 
Cholestrin is held in solution by the bile salts, and leaves 
the intestines with the fasces. 
The salts are sodium and potassium chloride, calcium 
phosphate, magnesia and iron. _ 
The acid secretion of the stomach on entering the intes¬ 
tines is neutralized by the alkalinity of the bile and pancreatic 
fluids, which cause a precipitate of acid-albumen and peptones 
to be thrown clown. . . , | 
The uses of bile are (i) slight action on converting starch 
into sugar; (2) assists in emulsifying and saponifying fats, but 
to a much less extent than the pancreatic fluid ; (3) assists in the 
absorption of fats. Owing to the peculiar power possessed by 
the bile salts, a membrane saturated with it allows an emulsion 
of fat to pass more readily through than if kept moistened 
with water); (4) increases peristalsis. (By its stimulating actions j 
it excites the muscles of the intestines to increased action); 151 
moistening and lubricating. (The bile adds to the ingesta a sup¬ 
ply ol fluid and mucus, which moistens and lubricates the 
