92 Cellulose 



general chemistry of lignification than the woods, which are, of 

 course, complex structures and subject to continuous modifica- 

 tion with lapse of time and in adaptation to the varying neces- 

 sities of the plant. For this, amongst other reasons, the jute 

 fibre has been more thoroughly investigated than the woods. 

 The results of these investigations will therefore be reproduced 

 at some length. It will simplify the treatment of the subject 

 if we first give a brief account of the fibre-substance in theo- 

 retical terms ; afterwards the methods of investigation by which 

 the theoretical conclusions have been established will be given 

 in greater detail, and in strict sequence of the lines upon which 

 the celluloses proper have been described. 



Lignocelluloses. (i) The Jute Fibre. The jute 

 fibre-substance differs strikingly in composition and re- 



f TT 



actions from the celluloses. With its higher ratio, viz. 



47j 5 



there are associated the characteristics 



__ 



O 47-9-47-2 



of an unsaturated compound i.e. it contains G=C groupings, 

 and these are localised in C 6 rings. These rings are, further, 

 of ketonic or quinonic character (containing a CO group), and 

 appear to be linked, by O, into complexes of the magnitude of 

 C 18 . They combine readily with chlorine, in presence of water, 

 and the resulting quinone chlorides are bodies of definite 

 properties and reactions. 



A second characteristic constituent of the fibre-substance 

 is a furfural-yielding complex, which appears to be an oxycellu- 

 lose derivative, a polyanhydride passing by hydration into an 

 oxycellulose of the ordinary type. 



The third main constituent is the cellulose of the fibre, 

 which can only be isolated by chemical treatments selectively 

 attacking the ' non-cellulose ' in which the two previously de- 

 scribed constituents are comprised. The reagents available for 



