Secretion of Bile. 413 



soluble in water. In addition to its presence in bile it has been 

 found in the placenta of the bitch. The test for bile coloring 

 matter is made bj' placing a drop of the suspected liquid on a 

 white porcelain plate and adding a drop of impure, brown, nitric 

 acid (nitric and nitrous acids). If bile is present there is pro- 

 duced a beautiful play of colors passing from the green of biliver- 

 din, through blue, violet, red, and ending in yellow. 



With regard to the formation of bile pigments in morbid con- 

 ditions it may be noted, that agents which dissolve the red blood 

 globules (such as bile-acids or water), when injected into the 

 veins determine the appearance of bile pigment in the urine 

 (Frerichs, Kuhne). When we consider that an animal (dog) 

 secretes -^ of its body weight daily of bile, and that nearly all of 

 this is re-abSorbed from the intestines, we can realize this as an 

 important source of bile and urinary pigments. 



Of the bile acids, taurocholic is the most abundant in the 

 bile of man, birds, and of many mammals and amphibians, while 

 glycocholic acid is the more plentiful in the: ox and pig. It is 

 absent in sucklings. The taurocholic acid has been found to 

 prove most destructive to red blood corpuscles, and in strong 

 solution is distinctly antiseptic, checking the development of 

 bacteria, of the alcoholic and lactic fermentations and of the 

 tryptic and diastatic action of pancreatic juice. 



The.se are conjugate acids, formed by the union of cholic 

 acid with taurin and glycin respectively, and they are found 

 almost exclusively, in combination with soda in the bile. They 

 are found in the liver and do not accumulate in the blood when 

 the liver has been removed. They increase under an albuminous 

 diet. 



The test for bile acid, is to take the suspected liquid from 

 which all albumen has been precipitated, add a few drops of 

 solution of cane sugar, shake into a froth, and pour sulphuric 

 acid, drop by drop, down the side of the test tube. A reddish 

 purple color appears in the froth, and shows two aksorp- 

 tion* bands at E and F. Any albumen left in the liquid will give 

 the same color, but only one absorption band. 



The secretion of bile is more abundant on animal than on 

 vegetable food, and on albuminous than fatty. It ceases during 

 hunger, but is increased by ingestion of water. Its solids are 



