1 78 Cellulose 



since Sachsse definitely propounded the view that the ligno- 

 celluloses are products of metabolism of cellulose. 



Comparing cellulose, Ci 8 H 30 O 15 , withlignone calculated to 

 a C 18 formula, viz. C 18 H 24 O 10 , the latter could be formed from 

 the former by dehydration ( 3H 2 O)and deoxidation ( O 2 ). 

 Sachsse preferred to formulate the process hypothetically as 

 under (' Farbstoffe,' &c. p. 146) 



C 24 H 40 O2o C 6 H 6 O 5 5H 2 O = Cj 8 H24O 10 | 



Cellulose Lignone 



the unknown complex C 6 H 6 O 5 undergoing further change, 

 either oxidation to CO 2 , or condensation to aromatic products 

 (tannins). This view is based entirely upon physiological 

 evidence, the chemistry of the process being hypothesis, pure 

 and simple. But we are now in a position to supply a more 

 substantial and consistent chemical basis. 



(1) The celluloses isolated from the lignocelluloses are all 

 oxycelluloses i.e. contain furfural-yielding groups. Oxidation 

 of the celluloses upsets the molecular equilibrium ; the oxy- 

 products are relatively unstable, and easily condensed to closed 

 chain derivatives. The celluloses also contain, in certain cases, 

 methoxyl groups. 



(2) The non-cellulose contains, in addition to the closed 

 hexene rings and methoxyl groups, a characteristic and con- 

 densed cellulose derivative. This group we can only diagnose 

 by indirect means. But a careful review of the evidence leaves 

 no doubt that the cellulose on the one hand, and keto R. 

 hexene derivatives on the other, regarded as extreme members, 

 are connected by an intermediate product or group of products, 

 which can be transformed (a) into cellulosic derivatives ; (&) into 

 acid products of low molecular weight, chiefly acetic ; (c) into 

 closed ring compounds, amongst which furfural is prominent. 



It is impossible to draw any line of separation between 

 these main groups : the ' intermediate ' constituent in seme 



