CONSTITUENTS OF COTTON-FIBRE. 115 



acids in brown flocks. When the substance in a finely 

 divided state, as obtained by precipitation from its alkaline 

 solution with acid, is exposed for some time to the action 

 of chlorine, its colour changes gradually from brown to pale 

 yellow. After being filtered off" and washed with water, the 

 product of the action dissolves easily in alcohol, and is left 

 on evaporation as a brown transparent resin^ which con- 

 tains chlorine, but in other respects closely resembles the 

 original substance. 



The analysis of this colouring matter led to the follow- 

 ing results : 



I. 0'3735 grm. prepared from East-Indian cotton and 

 dried at ioo° C. gave 07980 grm. carbonic acid and 0*2160 

 grm. water. 



0*5200 grm. burnt with soda-lime gave 0'6655 grm. 

 double chloride of platinum and ammonium. 



II. 0*3745 grm. of the same specimen gave 0*7985 grm. 

 carbonic acid and o*2i6o grm. water. 



III. 0*3925 grm. obtained from American cotton gave 

 0*8400 grm. carbonic acid and 0*2085 grm. water. 



0*5800 grm. gave 0*4820 grm. chloride of platinum and 

 ammonium. 



IV. 0*3845 grm. of the same gave 0*8245 grm. carbonic 

 acid and 0*2010 grm. water. 



0*7000 grm. gave 0*5920 grm. chloride of platinum and 

 ammonium. 



These numbers correspond in 100 parts to 



I. II. III. IV. 



C 58-27 58*11 58*36 58*48 



H 6-42 6*40 5*90 5*8o 



N 8-03 5*22 5-31 



O 27*28 30*52 30*41 



lOO'OO lOO'OO lOO'OO 



It will be seeen that the composition of the substance 

 varied, especially as regards the nitrogen, much more than 



I 2 



