FORMATION OF INDIGO-BLUE. 237 



C M H90 N0 23 is probably a mixture in equal proportions of 

 indicasine and oxindicasine. By decomposition of the lead 

 compound with sulphuretted hydrogen and evaporation of 

 the filtered liquid this substance is obtained in the form of a 

 brown syrup, which cannot be distinguished in appearance or 

 properties from oxindicanine or oxindicasine. 



I did not enter into a more minute examination of these 

 bodies, since their formation from indican is the only point 

 of interest in their history. 



