212 Cellulose 



and friable condition of the more ' condensed ' products. The 

 limit is obviously determined by the inability of such acids to 

 enter into any permanent synthetical combination with the con- 

 stituent groups of the wood-substance, which remain therefore 

 open to mutual interaction ; hence their further condensation, 

 and the building up of more resistant forms of lignocelluloses. 

 The reaction with nitric acid, on the other hand, is of a totally 

 different order : the acid hydrolyses and oxidises in the first 

 instance, but the specific and characteristic decomposition which 

 ensues (described in detail, p. 146) is the result of direct synthesis 

 of the lower oxides of nitrogen with the lignone groups. The 

 final products of resolution of the non-cellulose, or lignone, 

 are the simplest acids carbonic, acetic, and oxalic. 



The extreme oxidising action of nitric acid has been investi- 

 gated by Wheeler and Tollens (Annalen, 267, 367) in the case of 

 pine-wood, the wood being heated for 6 hours at 90-100, with 10 

 times its weight of nitric acid (1-4 sp.gr.) diluted with water. The 

 lignone constituents are, of course, entirely broken down in the 

 reaction, the greater proportion of the cellulose also. The residue 

 was an oxycellulose, amounting to 17 p.ct. of the weight of the wood, 

 having the composition : 



Calc. C, 6 H eo O ai 

 =6C.H 10 0.+0 



C 43*4i .... 4372 

 H 6-19 .... 6-07 

 O 50-40 .... 50-20 



Its properties were those of the oxycelluloses obtained by the 

 action of nitric acid upon cotton. 



The peculiar feature of this oxidation is the survival of a 

 residue so little different in empirical composition from the wood 

 cellulose itself. 



The results of these various treatments confirm entirely the 

 views advanced as to the constitution of the lignocelluloses, 

 and, conversely, a grasp of these views enables us to predict, 

 with a satisfactory approximation, the results of treatments not 

 specifically investigated. 



