Technical Chemistry. 2 ae 
oring matter in the bottom of the retort as a beautiful bronze-colored 
substance. 
The aniline purple prepared according to the process just described, 
although suitable for practical purposes, is not chemically pure. If 
required pure, it is best to boil it in a large quantity of water, then filter 
the resulting colored solution, and precipitate the coloring matter from it 
by means of an alkali. The precipitate thus obtained should be collected 
on a filter washed with water until free from alkali, and dried. When 
dry, it is to be dissolved in absolute aleohol, the resulting solution filtered, 
and then evaporated to dryness over the water-bath. us obtained, 
