208 MR. E. SCHUNCK ON THE 



difuscine being precipitated in combination with the respective 

 bases. When indifuscine is heated in a platinum crucible the 

 whole mass begins to heave and is kept in a state of agitation 

 for a few moments, in consequence probably of an evolution 

 of gas at the points of contact with the metal, whereupon it 

 burns but without melting and leaves a considerable quantity 

 of charcoal, which burns away with difficulty without leaving 

 any ash. When heated in a tube it gives fumes having a 

 smell like that of burning turf besides a little oily sublimate, 

 unmixed with anything crystalline. Concentrated sulphuric 

 acid dissolves indifuscine forming a brown solution, which on 

 being heated evolves sulphurous acid. A boiling solution of 

 bichromate of potash to which sulphuric acid is added dis- 

 solves and decomposes it rapidly with an evolution of gas, 

 the chromic acid being reduced to oxide of chromium. On 

 being treated with boiling dilute nitric acid indifuscine is 

 decomposed with a disengagement of nitrous acid, giving a 

 yellow liquid which on evaporation yields crystals of oxalic 

 acid. The mother liquor of these crystals on being neutral- 

 ised with carbonate of potash and evaporated gives brownish - 

 yellow crystals, which detonate when heated and give with 

 acetate of lead, nitrate of silver, and sulphate of iron, reac- 

 tions showing them to consist of picrate of potash. When 

 finely powdered indifuscine is suspended in water and sub- 

 jected to the action of chlorine it is converted into a yellow 

 flocculent substance containing chlorine, which is insoluble in 

 boiling water, but dissolves easily in boiling alcohol forming 

 a brown solution, which on spontaneous evaporation leaves a 

 light brown amorphous residue. 



When the indican submitted to decomposition with acids 

 has not been purified, the quantity of indifuscine formed far 

 exceeds that of the other products of decomposition, which 

 with the exception of indigo-blue are always produced in com- 

 paratively small quantities. In this case a great part of the 

 indifuscine owes its origin to the action of the acid on a body 



