368 DR. EDWARD SCHUNCK ON THE 



treated in the manner described in the paper just referred 

 to. It was found to consist of the same substances as the 

 precipitate obtained from the alkaline lye with which ordi- 

 nary Indian or American cotton has been treated, viz. : — 

 cotton wax, fusing at the same temperature and having the 

 same properties as that from ordinary cotton ; a crystalline 

 fatty acid, apparently identical with that previously ob- 

 tained ; pectic acid, parapectic acid, and colouring -matters. 

 It is to the latter that the cotton owes its colour; for this 

 colour is removed to a great extent by treatment with 

 alkali, and is again found tinging the precipitate produced 

 on the addition of acid; and I therefore examined them 

 with more care than the other constituents of the precipi- 

 tate. Of these colouring-matters two may be distinguished. 

 One of them is easily soluble in alcohol and is obtained on 

 evaporating the solution as a dark brown, shining, trans- 

 parent resin. The other is almost insoluble in cold alcohol, 

 but dissolves in boiling alcohol, and is deposited, on the 

 solution cooling, in the form of a light-brown powder. 

 Their general properties are the same as those of the ana- 

 logous colouring-matters from ordinary cotton. They con- 

 sist, like these, of carbon, hydrogen, nitrogen, and oxygen ; 

 but the relative amounts of the constituents are slightly dif- 

 ferent. The analysis of the colouring-matter easily soluble 

 in alcohol led to the following results : — 



0*4378 grm. of the substance, dried at ioo° C, gave 

 0*9346 grm. carbonic acid and 0*2138 grm, water. 



0*9958 grm., burnt with soda-lime, gave 0*5920 grm. 

 double chloride of platinum and ammonium. 



In 100 parts it contained, therefore, 



C 58-22 



H 542 



N 373 



O 3263 



