106 



CRYSTALLIZABLE NITROGENOUS MATTERS. 



Fig. 22. 



(C 24 H 40 5 ), the same body produced by a similar process from glyco- 

 cholic acid. The change here also takes place with the assumption 

 of the elements of water, as follows : 



Taurocholic acid. Taurine. Cholic acid. 



C 26 H 45 NS0 7 + H 2 = C 2 H 7 NS0 3 + C 24 H 40 5 - 

 Sodium taurocholate, like the preceding biliary 

 salt, is soluble in water and in alcohol, and insoluble 

 in ether. It is extracted from the bile by a similar 

 process to that already described, and, after precipita- 

 tion by ether, crystallizes in slender needles, much 

 like those of the glycocholate. It may be distin- 

 guished, however, and separated from the last-named 

 substance, when in company with it, by its reaction 

 toward the salts of lead. It is not precipitated from 

 its watery solution by the neutral, but only by the 

 tribasic acetate. If a watery solution, therefore, con- 

 taining both salts be precipitated by neutral lead ace- 

 tate, the filtered fluid will contain the sodium tauro- 

 cholate alone. In alcoholic solution it rotates the 

 plane of polarization toward the right 24.5. 



The two biliary salts are associated in the bile in 

 varying proportions. Generally the glycocholate may 

 be said to preponderate in the bile of the ruminant 

 animals, taurocholate in that of the carmvora. In 

 dog's and cat's bile, the taurocholate exists alone. In 

 human bile it appears that both substances may be 

 present, sometimes one of them being the more abun- 

 dant, sometimes the other ; according to some writers the taurocholate 

 existing alone or in larger proportion (Gorup-Besanez, Hoppe-Seyler, 

 Robin, Hardy), according to others the gtycocholate (Bischoff, Lossen, 

 RankeJ. In the observations of Jacobsen, 1 on a case of biliary fistula 

 in man, the glycocholate was shown to be a constant ingredient, while 

 the taurocholate was either absent, or, if present, varied in quantity. 

 We have also found human bile to contain the glycocholate without 

 the presence of taurocholate. 



The biliary salts are formed in the glandular tissue of the liver and 

 discharged with the bile. According to the observations of Ranke on 

 a man with biliary fistula, the average quantity of the organic acids of 

 the bile thus produced, by a man weighing 65 kilogrammes, would be a 

 little over 15 grammes per day. They are not discharged with the feces, 

 but are changed in the intestine, and, probably, reabsorbed under another 

 form by the blood. 



Creatine, C 4 H 9 N 3 2 , from x^, flesh. 



This is a neutral crystallizable substance, which exists very generally 

 in the muscular tissue, both voluntary and involuntary, of man and 



SODIUM TAU- 

 ROCHOLATE, from 

 alcoholic extract of 

 dog's bile, crystalliz- 

 ing at the bottom of 

 a test-tube. 



Kevue des Sciences Medicales, 1874, vol. iii. p. 85. 



