72 DR. EDWARD SCHUNCK ON SOME 



by the ammonia was precipitated by acid in thick flocks, 

 which, after being filtered off, washed, and dried, were 

 treated with ether. The ether left some brown powder un- 

 dissolved, which was separated by filtration. The liquid 

 was evaporated, and the residue was treated again with 

 ether, in order to separate a little more of the brown 

 powder. The substance was then introduced into a hot 

 solution of carbonate of ammonia, which, if not too con- 

 centrated, dissolved the greatest part of it, leaving only 

 some brown powder behind. If, as sometimes happened, 

 the solution of carbonate of ammonia was not sufficiently 

 dilute, very little was dissolved by it, the greatest part of 

 the substance sinking to the bottom of the vessel as a viscid 

 resinous mass, which dissolved, however, almost entirely 

 on pouring off the liquid and adding pure water. The 

 addition of acid to the filtered solution produced a brown 

 flocculent precipitate, which was filtered off, washed with 

 water, and treated with cold alcohol. The filtered alcoholic 

 solution left, on evaporation, a resinous body hardly to be 

 distinguished in appearance from the preceding, and which 

 I will denote by the letter B. 



The matter insoluble in ether, constituting by far the 

 larger part of the whole mass, was first treated with a little 

 cold alcohol, to which it communicated a dark-brown colour. 

 The filtered alcoholic liquid left, on evaporation, a brown 

 resinous residue, which was not further examined, since it 

 was sure to contain some of that well-known product of 

 decomposition which, is formed by the action of caustic 

 fixed alkalies on alcohol, and which, being also resinous, I 

 saw no prospect of being able to separate from any product 

 derived from indigo-blue which might be mixed with it. 

 The portion left undissolved by the cold alcohol was, after 

 being dried, a brovm powder, which consisted of three sub- 

 stances. In order to separate these from one another, the 

 mixture was first subjected to the action of boiling dilute 



