5 8 Cellulose 



The reaction requires further systematic research in the light of 

 our increased knowledge of the constitution of the simpler carbo- 

 hydrates and the simple products of their oxidation. 



(2) Chromic acid, in dilute solutions, attacks cellulose with 

 extreme slowness ; in presence of mineral acids oxidation 

 proceeds more rapidly, but at ordinary temperatures is still 

 very slow. The action is, therefore, easily controlled within any 

 desired limit, the oxidation being in this case of course directly 

 proportionate to the amount of CrO 3 presented to the fibre. 

 The oxidation is accompanied by disintegration, and the 

 insoluble product is an oxidised cellulose, or oxycellulose, the 

 yield and composition of which bear a simple relation to the 

 amount of oxidation to which the cellulose is subjected. Its 

 properties are similar to those of the oxycellulose above 

 described. It dissolves in a diluted mixture of sulphuric and 

 hydrochloric acids (57 p.ct. H 2 SO 4 , 5-5 p.ct. HC1), and on 

 diluting and distilling with HC1 of i'o6 sp.gr., is decomposed 

 with formation of furfural, C 4 H 3 O.COH, the yield of this alde- 

 hyde being proportionate to the state of oxidation of the 

 product. 



This is illustrated by the subjoined results of observations : 



Weight of CrO 3 employed Yield of Yield of furfural 



cellulose oxycellulose p.ct. of oxycellulose 



47 I '5 93 'O 4'i 



47 3*o 8 7*o 6-3 



47 4'5 82-3 8-2 



(Berl. Ber. 26, 2520.) 



The first effect of treatment with CrO 3 appears to be that of 

 simple combination ; reduction to the Cr 2 O 4 then ensues, and the 

 further deoxidation requires the presence of a hydrolysing acid. 



From the statistics of the reaction it appears there is little ' de- 

 struction ' of the cellulose ; and, as the oxidation is not attended 

 by evolution of gas (CO a ), we may assume that the reaction 

 consists simply in oxidation with the fixation of water. A certain 



