Compound Celluloses 157 



upwards) nor with thickening of cell wall (incrustation) ; pre- 

 serves essential features through wide range of differences in 

 empirical composition, resulting from differences in conditions 

 of growth, (b) General resistance to resolution (into proximate 

 constituents), by the action of solvents and hydrolytic agents 

 generally, (c) Behaviour in synthetic reactions, chiefly in ferric 

 ferricyanide reaction and formation of nitrates ; resistance of 

 molecule to resolution. 



(2) GENERAL CHARACTER OF LIGNOCELLULOSE CONSIDERED 

 AS A WHOLE. The alcoholic characteristics of the lignocellulose 

 are inferior t'o those of cellulose : the reactive OH groups are 

 fewer in proportion ; CO groups of aldehydic, ketonic, and acid 

 function are present in union, more or less, with the more basic 

 OH groups. Tho characteristic reactions of the compound 

 (lignone group) are those of unsaturated compounds, and it is, 

 by comparison with the celluloses, greedy of oxygen. 



(3) CONSTANTS OF THE FIBRE IN REACTION. In this con- 

 nection we refer only to such reactions as throw light upon 

 the relationships of constituent groups, and therefore reactions 

 of decomposition. 



Cellulose. Cl method : average yield, 75*0 p.ct. ; raised, by 

 minimising conditions tending to hydrolysis and oxidation, to 

 78-82 p.ct. 



Br method : average, 72*0 p.ct. ; may be raised similarly 

 to 74-76 p.ct. 



Nitric acid (dilute) method, 63-66 p.ct. Alkali method, 

 56-60 p.ct. Bisulphite method, 60-63 P- c ^ 



The cellulose is a variable, the variations being due to 

 greater or less hydrolysis. The lignocellulose contains a 

 cellulose of resistant characteristics and a cellulosic constituent 

 which is either isolated as cellulose or dissolved with the 

 lignone complex according to the treatment. This latter 



