88 BILE. 



contain S'225 of fat, while that of the hepatic venous blood con 

 tains only 1'885. 



I do not purpose reverting here to the chemical grounds 

 which appear to support the view that cholic acid is formed from 

 oleic acid, but would simply observe, in relation to this subject, 

 that I have never succeeded in producing sebacic acid by dry 

 distillation from cholic acid, and, on the other hand, that I have 

 convinced myself that not only the acids of the butyric acid 

 group (Redtenbacher), but likewise those of the succinic acid 

 group, more especially lipic and suberic acids, may be produced 

 from cholic acid by the action of nitric acid, in the same manner 

 as from oleic acid (Laurent). Moreover, Kunde, as already ob- 

 served, found that not merely the fat of frogs, but also every 

 other animal or vegetable fat which is rich in olein, yields an 

 intense purple-violet colour with sulphuric acid and sugar; it 

 does not occur with fats that are free from olein, and is most per- 

 fectly exhibited with pure oleic acid. This reaction of the oleic 

 acid only differs, according to my experience, from that of cholic 

 acid in occurring more slowly, and requiring the access of atmo- 

 spheric air. As I did not perceive that there was any absorption 

 of gas, I thought that the oleic acid might be contained in the 

 cholic acid, in the modification of elaidic acid ; but the latter acid 

 yielded the same reaction as cholic acid with sugar and sulphuric 

 acid, although less rapidly. 



M. S. Schultze* has recently made the same observation with 

 regard to olein. He also showed that the protein-bodies yielded a 

 similar violet colour when treated with sugar and sulphuric acid ; 

 and I have noticed the same circumstance in many ethereal oils, 

 as, for instance, oil of turpentine and oil of caraway.f Petten- 

 kofer's test is, however, by no means to be rejected on this 

 account, as it merely requires the same amount of caution in its 

 application that is indispensable for the exhibition of every other 

 chemical reaction. 



The fat of the hepatic venous blood, when treated with sugar 

 and sulphuric acid, yields the same reaction as that of the portal 

 blood ; and, when the experiment is conducted with care, we can 

 scarcely fail to arrive at the conviction that no bile is contained in 

 either kind of blood. The reaction does not ensue excepting with 

 that portion of these two kinds of blood which is soluble in ether, 



* Ann. d. Ch. u. Pharm. Bd. 71, S. 270. 



t Kunde, De hepatis ranarum extirpatione diss. inaug. med. Berol. 1850. 



