102 MR. EDWARD SCHUNCK ON SOME 



cohol, was decomposed with warm dilute hydrochloric 

 acid, which left undissolved a dark-brown, semifused 

 mass. This mass, after being kneaded in hot water and 

 thoroughly freed from barium-salt, was treated with boil- 

 ing alcohol. The alcohol generally left some brown powder 

 undissolved, consisting of colouring-matter B ; and an 

 additional quantity was usually deposited from the alcohol 

 on cooling. Having been filtered off, it was purified by 

 dissolving it in a sufficient quantity of boiling alcohol, as 

 above described. The filtered liquid left, on evaporation, 

 a dark-brown resinous mass, which was reduced to a fine 

 powder, and then agitated in a flask with ether. The 

 ether dissolved only a very small portion of the mass, but 

 it served to remove a trace of fatty acid contained in it. 

 The ether, on evaporation, left a brown fatty residue, 

 which, after combination with baryta and treatment of the 

 compound with boiling alcohol, as just described, yielded 

 a quantity of pure fatty acid. The portion left undissolved 

 by the ether was treated with cold alcohol, which dis- 

 solved the greatest part of it. The dark-brown solution, 

 after being filtered from a small quantity of colouring- 

 matter B, which was usually present, was evaporated to 

 dryness, when it left a dark-brown, shining, resin-like 

 residue, consisting of the colouring-matter A. 



The greatest part of the precipitate produced by acid in 

 an alkaline extract of cotton is insoluble in alcohol. This 

 portion, when dry, has the appearance of a brown, friable, 

 earthy mass, among which cotton filaments, particles of 

 woody fibre, and other impurities derived from the cotton 

 may be seen. When burnt, it leaves a considerable quantity 

 of ash. Its weight, when dry, amounted, in the case of 

 East-Indian cotton, to 77 per cent, of that of the entire 

 precipitate, in that of American cotton to 66 per cent. 

 Though much lighter in colour than the precipitate before 

 treatment with alcohol, it still contains a quantity of 



