298 Dr. Schunck on some Products 



with cold alcohol. The filtered alcoholic solution left, on eva- 

 poration, a resinous body hardly to be distinguished in ap- 

 pearance 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 alco- 

 hol, 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 undis- 

 solved by the cold alcohol was, after being dried, a brown 

 powder, which consisted of three substances. In order to se- 

 parate these from one another, the mixture was first subjected 

 to the action of boiling dilute caustic soda-lye, in which one 

 of the three was found to be insoluble. The alkaline liquid, 

 which was of a dark- brown colour, was filtered, and the residue 

 left undissolved was again treated with alkali in order to 

 remove the whole of the soluble portion, and it was then 

 treated with a boiling alcoholic solution of caustic soda, in 

 which the greatest part dissolved with ease. The dark-brown 

 solution was filtered and then mixed with an excess of hydro- 

 chloric acid, which precipitated the greatest part of the sub- 

 stance as a dark-brown powder. This was collected on a 

 filter, washed with alcohol until all the acid and chloride of 

 sodium were removed, and dried. This body I will distin- 

 guish by the letter C. The caustic soda-lye contained the two 

 other substances in solution ; and it was accordingly mixed 

 with an excess of acid, which produced an abundant brown 

 flocculent precipitate. This was collected on a filter, well 

 washed with water, and then treated with a boiling solution 

 of acetate of soda, which dissolved part of it, thereby acqui- 

 ring a brown colour. The liquid was filtered boiling hot, and 

 the residue was treated with fresh solution of acetate of soda, 

 the process being repeated as long as the boiling liquid ac- 

 quired any colour. The residue left undissolved by the ace- 

 tate of soda was treated with boiling alcohol containing a 

 little ammonia, in which it dissolved with ease, forming a 

 dark-brown solution, from which the greatest part was again 

 precipitated on the addition of an excess of hydrochloric acid 

 as a brown powder. This was filtered off, well washed with 

 alcohol, and dried. This body may be denoted by the letter D. 

 The substance held in solution by the acetate of soda was 



