FORMATION 19i 



ducts of decomposition seemed to be formed, when nitric acid 

 was used. 



[a whatever manner the products insoluble in water were 

 obtained, I always adopted the same method of treatment for 

 turpose of separating them from one another, a method 

 indeed essentially the same as that employed by 

 Berzelius for the separation of the constituents of crude indigo. 

 The whole of the acid used in the process having been care- 

 fully removed by means of cold water, the mass left on the 

 filter was treated with dilute caustic soda. This dissolved a 

 great portion forming a dark brown opaque liquid, which was 

 filtered ,*rom the insoluble matter. The latter was treated 

 again with caustic soda, the action being now assisted by heat, 

 and the process was repeated until nothing more was dissolved. 

 The liquid on being mixed with an excess of muriatic acid let 

 B voluminous flocculent precipitate of a brown colour, which 

 being collected on a filter and washed with water was 

 ith a boiling mixture of alcohol and ammonia. This 

 sometimes dissolved the whole of it, sometimes only a part. 

 The insoluble portion, w T hcn there was any present, had the 

 appearance of a dark brown powder, and consisted of the body 

 to which I have given the name of Indihumine, After having 

 been treated repeatedly with alcohol and ammonia, until 

 nothing more was dissolved and then with muriatic acid, and 

 lastly washed with water, it was considered pure. The 

 alcoholic liquid filtered from it was dark brown. On adding 

 an excess of acetic acid, an abundant dark brown deposit 

 was formed, consisting of a substance which 1 h*».d not pre- 

 viously observed, and to which I propose to apply the term 

 Indifuscine. It was collected on a filter, washed first with 

 alcol hot water until all the acetate of ammonia 



and acetic acid were removed, and lastly agitated with a little 

 cold alcohol, filtered off and dried, when it had the appearance 

 of a dark brown or reddish-brown powder. By repeating the 

 process of solution in alcohol and ammonia and precipitation 

 2 c 



