n6 Cellulose 



by the fibre-substance in very large quantity (50 p.ct. of its 

 weight). 



(8) Chromic acid, in aqueous solution, combines with the 

 lignocellulose, and is then very slowly reduced to the inter- 

 mediate oxide (CrO 3 .Cr 2 O 3 ). 



(9) Potassium permanganate is rapidly reduced, the MnO 2 

 produced colouring the fibre a deep brown. After treatment 

 with sulphurous acid, which removes the oxide, the lignocellu- 

 lose will be found to have been bleached by the treatment. 

 On repeating this treatment once or twice, with dilute solution 

 of KMnO 4 , the lignocellulose is obtained of a cream or greyish- 

 white colour, the loss of weight sustained in the bleaching 

 being small (2-4 p.ct.). 



Compounds of Jute Lignocellulose. The fibre- 

 substance itself being a complex or compound cellulose, and 

 susceptible of decomposition (a) by hydrolytic treatment in 

 which, however, the union of the constituent groups is pre- 

 served and (b) by reagents which selectively attack the con- 

 stituent groups, it is obvious that we are limited in the prepa- 

 ration of compounds which may be regarded as compounds of 

 the lignocellulose molecule as a whole. We shall first describe 

 those which result from reactions of the OH groups of the 

 lignocellulose. These are more active than in the celluloses. 

 We have already pointed out that the fibre combines freely 

 with colouring matters. The phenomena of dyeing being 

 now well established, as the result of interaction of salt-forming 

 groups in fibre-substance and colouring matter, i.e. a species of 

 ' double salt ' formation, we may deduce from the considerable 

 and very general * affinity ' of the lignocelluloses for the coal- 

 tar colouring matters, that they contain OH groups of both 

 acid and basic function, and much more disposed to reaction 

 than those of the celluloses. 



Absorption nf acids and alkalis from dilute aqueous solutions. 



