232 MR. E. SCHUNCK ON THE 



the dissolved lead has been removed with sulphuretted hydro- 

 gen leaving on evaporation a residue which is insoluble in 

 alcohol. It differs however in composition according as the 

 solution of indican has been evaporated spontaneously or with 

 the assistance of heat. The body which is formed when a 

 watery solution of indican is spontaneously evaporated in 

 contact with the air, I propose to call 



OXINDICANINE. 



So much of this body is produced during the preparation 

 of indican, that I found it unnecessary to prepare it purposely. 

 When the residue left after the evaporation of the watery 

 solution of indican by means of a current of air, as described 

 above, is treated with cold alcohol, the greatest part of the 

 oxindicanine formed during the process remains undissolved. 

 It may be purified simply by dissolving it in a little water 

 and precipitating again with a large quantity of alcohol. Its 

 appearance is that of a brown glutinous substance, which on 

 being left to stand over sulphuric acid becomes almost dry 

 and assumes the appearance of gum. It is insoluble in abso- 

 lute alcohol and only slightly soluble in dilute alcohol. When 

 heated on platinum it swells up very much and burns leaving 

 a considerable carbonaceous residue. It yields when heated 

 in a tube strong smelling fumes but only a slight trace of 

 crystalline sublimate. Its taste is nauseous but not bitter. 

 Its watery solution gives with acetate of lead a copious dirty 

 yellow precipitate, and the filtered liquid gives a pale prim- 

 rose-yellow precipitate on the addition of ammonia or of a 

 large excess of alcohol. When the watery solution is mixed 

 with sulphuric acid and boiled it slowly deposits brown flocks, 

 which have the properties of indifuscine, while the liquid con- 

 tains indiglucine. For the purpose of determining its com- 

 position I employed the lead compound, prepared by adding 

 acetate of lead to the watery solution, filtering and washing 

 with water. 



