Compound Celluloses 123 



The results obtained are, however, by no means constant, 

 but vary considerably with variations in the conditions of 

 treatment. The causes of these variations lie in the complex 

 character of the lignocellulose. In the celluloses alcoholic 

 characteristics predominate ; in the lignocelluloses the presence 

 of phenolic OH groups, of CH 2 .CO and CH 2 .CO.O groups, 

 and of ketonic oxygen (see p. 137) must largely modify 

 the alcoholic functions of the cellulosic OH groups. They 

 are, in fact, in condensed union with these more negative 

 groups, and this union is only partially resolved in certain 

 directions, and further cemented in others, by the alkaline 

 treatment. It is probable that the alkali may have the 

 effect of further condensing or synthesising the aldehydic 

 groups. 



It is evident, on the other hand, that the entire molecule 

 is opened up for the entrance of water molecules, and the 

 prominent result of the reaction is the consequent hydration of 

 the lignocellulose. It is this aspect which leads us to describe 

 the reaction under the heading of the * Compounds of the 

 Lignocellulose.' The attendant hydrolysis is a secondary 

 result which will be referred to subsequently. 



Compounds of the Lignocellulose with Metallic 

 Salts. We are still dealing with those synthetical reactions of 

 the lignocellulose (OH groups) which take place in presence 

 of water. The resulting compounds are necessarily of a 

 variable and ill-defined character, owing to the complex nature 

 of the lignocellulose, the tendency to selective reaction 

 with its constituent groups, and to consequent partial hydro- 

 lysis. 



The combinations already described as taking place with 

 the alkalis and non-oxidising acids are seen to be of a feeble 

 and transitory character. With many of the salts of the heavy 

 metals the reactions are more pronounced, but they are also 



