Compound Celluloses 147 



greatest quantity at the end of the reaction and as the tempera- 

 ture is raised to 100. (c) The presence of N 2 indicates a still 

 further deoxidation or hydrogenisation of the N to ammonia. 



(2) As regards the fibre- substance, the keto R. hexene 

 groups are rapidly oxidised, and entirely broken down. No 

 ' aromatic ' products are formed, and the result is in perfect 

 accord with the general view we have taken of their consti- 

 tution. 



The furfural-yielding complex and the fit-cellulose group 

 are more gradually resolved, and both probably contribute to 

 the large yield of acetic acid. It is obvious that the constitu- 

 tion of both groups is of a special type, unlike the normal 

 grouping of the carbohydrates. 



The reaction has been also studied in connection with 

 another group of the lignocelluloses viz. the woods and will 

 be again referred to (p. 212). 



Joint action of oxides of nitrogen and chlorine. F. Schulze's 

 method of eliminating the non-cellulose groups of the ligno- 

 celluloses, in the isolation and estimation of cellulose, has 

 been already described. It consists in a prolonged diges- 

 tion in the cold with nitric acid (ri sp.gr.), with addition of 

 a small proportion of potassium chlorate. The reaction has 

 not been investigated in regard to the by-products. The 

 mechanism of the decomposition will be evident from what 

 has been stated in regard to the actions of chlorine and of 

 nitric acid upon the lignocellulose. 



(?) ALKALINE OXIDANTS. The actions of this group of 

 reagents are of considerable technical importance, as upon 

 them depend the various bleaching methods in common 

 practice ; but they have not been sufficiently investigated to 

 throw light on theoretical points. 



Potassium permanganate acts, of course, as an oxidising 

 agent pure and simple. The limit of deoxidation in basic or 



I. 2 



