The Typical, Cellulose and the Cellulose Group 85 



agents. Thus after lengthened exposure to solutions of zinc- 

 sodium hyposulphite, prepared by the action of zinc dust upon 

 sodium bisulphite, the yield of furfural which is a measure of 

 the degree of oxidation was reduced, in the case of esparto 

 cellulose, from 12-6 to 8-9 p.ct. 



A still further deoxidation results from solution of these oxy- 

 celluloses as thiocarbonate, and regeneration of the cellulose 

 by heating the solution at 80-100. The regenerated cellulose 

 approximates to the normal, yielding only 2 p.ct. furfural 

 on hydrolysis. It is to be noted, however, that esparto cellu- 

 lose, in common with all the celluloses of this group, is partly 

 hydrolysed to soluble derivatives by this treatment ; the re- 

 generated cellulose amounting to 80 p.ct. of the original weight 

 dissolved. The soluble portions yield furfural on hydrolysis, 

 amounting (in a typical experiment) to 4/0 p.ct. of the original. 



The celluloses of this group are dissolved by concentrated 

 sulphuric acid to dark coloured solutions. On diluting and 

 boiling they are resolved into carbohydrates of low molecular 

 weight ; dextrose appears to be invariably formed, and in many 

 cases also mannose ; but only very small yields of either 

 carbohydrate have been so far obtained. 



Group (c). This includes the heterogeneous class of non- 

 fibrous celluloses which we have defined as of low resistance 

 to hydrolysis, being easily resolved by boiling with dilute acids, 

 and being also more or less soluble in dilute alkaline solutions. 

 This group has been but little studied, and therefore can only 

 be generally characterised. Physiological research has shown 

 that there are a large number of cellular, as distinguished from 

 fibrous ' celluloses,' which are readily broken down (hydrolysed) 

 by the action of enzymes within the plant itself, whether as a 

 normal or abnormal incident of growth. Thus in the germina- 

 tion of starchy seeds, the cell walls (cellulose) of the starch-con- 

 taining cells are broken down, as a preliminary to the attack 



