J94 MR. E. SCHUNCK ON THE 



with acid, its further purification was effected. The alcoholic 

 liquid filtered from the indifuscine was mixed with an alcoholic 

 solution of acetate of lead, when an additional quantity of the 

 same substance was precipitated in combination with oxide of 

 lead in brown flocks. The filtered liquid, containing an excess 

 of sugar of lead was mixed with ammonia, which gave a 

 brownish-yellow precipitate, consisting chiefly of indiretine in 

 combination with oxide of lead. This precipitate after being 

 filtered off was treated with dilute acetic acid, which removed 

 a considerable quantity of oxide of lead, and after being 

 again filtered off and washed, it was completely decomposed 

 with boiling dilute muriatic acid. The indiretine which was 

 separated collected in the boiling liquid in the form of brown 

 half fused masses, which were separated by filtration while the 

 liquid boiled, washed with boiling water and then treated with 

 a small quantity of cold alcohol. The alcohol acquired a dark 

 brown colour, and after being filtered from a little undissolved 

 indifuscine was evaporated to dryness, when it left the indiretine 

 in the shape of a brittle resinous residue, which was purified 

 by being again dissolved in cold alcohol. 



That part of the product of the action of acids insoluble in 

 caustic soda was usually of a dark bluish-purple colour. It 

 was treated with boiling alcohol until nothing more dissolved. 

 The alcoholic liquid, which had a dark brownish-purple colour, 

 was filtered boiling hot from the insoluble portion, consisting 

 chiefly of indigo-blue, and then mixed with ammonia and an 

 alcoholic solution of acetate of lead, which gave a brown pre- 

 cipitate consisting of oxide of lead in combination with indi- 

 fuscine, and such other products as had not been completely 

 extracted by the caustic soda. After being filtered from this 

 precipitate the liquid appeared of a beautiful purple colour. 

 It was mixed with an excess of acetic acid and distilled or 

 evaporated to about one quarter of its original volume, and 

 then mixed with a large quantity of water, which precipitated 

 the whole of the matter dissolved in it in the shape of dirty 



