18 CHEMICAL PHYSIOLOGY. 



producible from such ; while the other compound acid 

 yields as the second product of its cleavage glykokoll 

 or amido-acetic acid (C 3 H 5 N0 3 ), which is producible 

 artificially by various processes. The rational con- 

 stitution of the smaller nuclei is thus shown to be 

 well known ; but the same could not be said of cholic 

 acid. Glykokoll appears in an excretion as hippuric 

 acid (in which it is coupled with benzoic) but it is at 

 present uncertain whether this excreted glykokoll has 

 previously taken any share in the composition of bile 

 or not. Taurine, however, is consumed in the body, 

 and its sulphur appears in the excretion as sulphuric 

 acid. 



The coloured ingredients of bile are cholophaeine 

 or bilirubine, C 9 H 9 N0 3 , and bilifuscine, probably 

 C 9 H 11 N0 3 . By oxydation and loss of carbonic acid 

 cholophasine easily passes into biliverdine, C 8 H 9 N0 3 , 

 according to the formula, C 9 H 9 N0 2 + 20 = C 8 H 9 lSr0 3 

 + C0 2 . 



Cholesterine (C^H^O) occurring in the brain and 

 blood is no doubt excreted by means of the bile. It is 

 a polydynamic alcohol, capable of forming ethers 

 analogous to fats. Coloured matters, such as cholo- 

 nematine, boviprasine, fuscopittine, muscoprasine, 

 and ethochlorine, all possessing characteristic pro- 

 perties and spectra, and cholesterine are the main 

 residues of certain diseased processes which terminate 

 in the production of calculi. In a degeneration of the 

 liver, called bacony, considerable quantities of chole- 

 sterine remain stagnant in the parenchyma of that 

 organ. The choline of the bile is an organic base of 



