246 INFECTIONS OF THE DIGESTIVE TRACT 



may contain a considerable quantity of indol ; and owing 

 to imperfect absorption the urine may contain only 

 moderate quantities of indican. Upon the whole, how- 

 ever, if one considers the findings from day to day over 

 a considerable period of time, it holds true that there is a 

 rough relation between the indol formed in the intestine 

 and the quantity of indican excreted. In conditions of 

 health the absorption of moderate quantities of indol 

 from the intestine is followed by the rapid oxidation of 

 indol to indoxyl or some indoxyl compound, and this 

 oxidation is associated with or followed by a synthesis 

 with sulphuric acid, occurring mainly in the liver and 

 partly in the muscles, and which results in the produc- 

 tion of the indoxyl-potassium-sulphate of the urine. It is 

 the indoxyl-potassium-sulphate (or indican) of the urine 

 which on further oxidation yields indigo. Something is 

 now known in regard to the fate of indol in the organism. 

 While it is true that in general the aromatic compounds 

 of putrefaction are resistant to oxidation, it is probable 

 that indol when introduced in moderate quantities into 

 the organisms of carnivora and omnivora suffers a 

 break-down both in the pyrrol ring and the benzene 

 ring. That is to say, a portion of the indol is burned 

 completely in the organism. This view is based partly 

 on what has been found to be the case for phenols and 

 especially for cresol, 1 and partly as direct observations 

 on the facts of ingested indol. 



1 Blumenthal, " Biochemische Untersuchungen iiber Vergiftung 

 und Entgiftung bei der Lysolvergiftung," Biochem. Zeitschr., i, 

 p. 135, 1906. The author found that only from twenty to 

 twenty-five per cent, of the cresol introduced into the animal 



