154 THE CARBOHYDRATES 



acid substance ; the latter, when boiled with water dissolves, 

 leaving a neutral product which resembles a typical aldehydic 

 oxycellulose. This is regarded as being due to the oxidation 

 of an alcoholic group into cellulose molecule(see formulae, p. 56). 

 4. Action of Ferments. It has been shown by Brown and 

 Morris, in the case of malt, that the cell wall of the endosperm 

 cells which contain nutrient material are broken down by a 

 cellulose-dissolving ferment, a cyto-hydrolyst, before the 

 embryo can procure the food-stuff contained in these cells. 

 This enzyme, which is developed during the germination of 

 the seed, can be extracted from the malt by cold water, and 

 precipitated from this solution by alcohol. As another ex- 

 ample of the fermentative decomposition of cellulose may be 

 quoted the formation of marsh gas according to the equation 



C 6 H 10 5 + H 2 = 3 C0 2 + 3 CH 4 



which may be observed when vegetable matter is undergoing 

 slow decomposition under stagnant water. 



CHARACTERS AND PROPERTIES OF COMPOUND CELLULOSES. 



As already stated, the main characteristic of the group of 

 compound celluloses is that they are composed of one or other 

 form of cellulose combined with some other substances of a 

 non-cellulose nature. 



The nature of the cellulose constituent varies according to 

 the source from which it is obtained, one of the chief char- 

 acteristic differences between such different forms of cellulose 

 being their behaviour on boiling with hydrochloric acid ; thus 

 whereas cotton cellulose yields only about O'I-O'4 per cent of 

 furfurol, jute cellulose under similar conditions yields 3-0-6*0 

 per cent, and straw cellulose yields from 12-0-15-0 per cent; 

 for this reason the cellulose constituent is regarded as being 

 of the nature of oxycellulose. 



The Non-cellulose Constituent of compound celluloses may 

 vary very considerably in chemical nature, and on this fact 

 depends their classification'into 



(a] Lignocelluloses. 



(ft) Pectocelluloses. 



(c) Adipo- or Cuto-celluloses. 



