Compound Celluloses 193 



lose), it should be formed correlatively with the furfural-yielding 

 compounds ; and the quantitative relations of the two certainly 

 confirm this view. Thus the hypothetical decomposition may 

 be formulated as under : 



2 C 6 H 12 O 6 = 2C 5 H 10 5 + C 2 H 4 O 2 , 

 2x150 60 



and the pentosans of wood represent in effect a percentage 

 approximately five times that of the acetic acid obtainable 

 by simple hydrolysis. 



In the jute fibre also, the smaller proportion of the fur- 

 fural-yielding constituents is associated with a similar smaller 

 proportion of the acetic residue. The formation of both 

 therefore increases, paripassu, with age, which is in accordance 

 with the view of a common origin. 



(2) The celluloses, and the 'carbohydrates' generally, are 

 susceptible of the ' acetic condensation.' The normal cellu- 

 loses, however, require the application of drastic treatments, 

 e.g. fusion with alkaline hydrates or warming with concentrated 

 sulphuric acid, both of which treatments are of an oxidising 

 character. The oxycelluloses, on the other hand notably the 

 straw celluloses give a considerable yield of acetic acid 

 (together with furfural) on long boiling with 10 p.ct. sulphuric 

 acid. The maximum yield is obtained by dissolving the oxy- 

 cellulose in the concentrated acid in the cold, diluting and dis- 

 tilling. In this way the authors have obtained a yield of 

 9-10 p.ct. of the acid, calculated on the oxycellulose. 



These observations confirm the view that lignification is a 

 process of transformation taking place in oxidised celluloses, 

 or oxycelluloses, and following as a secondary result of the dis- 

 turbance of equilibrium set up by the oxidation. 



(3) In addition to acetic residues converted by hydrolysis 

 into acetic acid there appears to be a CO.CH 2 nucleus, a 

 dehydracetic residue, which is the source of the increased 



o 



