The Typical Cellulose and the Cellulose Group n 



addition of neutral dehydrating agents such as alcohol, sodium 

 chloride (and other salts of the alkalis), and even sugar. 

 From a study of these solutions, indeed, Erdmann concluded 

 (J. Pr. Chem. 76, 385) that they were not solutions of cellulose 

 in the strict sense of the term, the cellulose being rather 

 gelatinised and diffused through the solution as a highly 

 attenuated (hydrated) solid of this description. Cramer, on 

 the other hand, showed by osmotic experiments that this 

 inference was unfounded and that the solution of the cel- 

 lulose may be regarded as complete. According to modern 

 views on the subject of solution generally, and the solution 

 of colloids in particular, the lines drawn by the older inves- 

 tigators of these phenomena are of arbitrary value ; gelati- 

 nisation being expressed as a continuous series of hydrations 

 between the extreme conditions of solid on the one side and 

 aqueous solution on the other. This point will be further con- 

 sidered later on. 



The evidence goes to show that the solution process, though not 

 the result of an oxidation of the cellulose such as would be attended 

 by reduction of CuO is attended by a disturbance of the ' balance 

 of oxidation ' of the cellulose molecule. By prolonged contact with 

 the cuprammonium the cellulose does in fact appear to be oxidised 

 (to oxycellulose) (Prudhomme, J. Soc. Dyers and Col., 1891, 148). 



The ammonia also undergoes oxidation, and the cuprammonium 

 solutions, after keeping, will be found to contain a considerable 

 quantity of nitrite (ibid.). Cotton cellulose does not appear to be 

 hydrolysed by the process of solution, that recovered from the solu- 

 tion by precipitation by acids &c. having approximately the same 

 weight as that of the fibre originally dissolved. 



There are celluloses, on the other hand, which are partially 

 hydrolysed, and when reprecipitated the cellulose recovered is 

 found to be in defect, and the solution to contain dissolved carbo- 

 hydrates. 



Further investigation of these points is much needed, i.e. 

 quantitative determination of the oxidation and hydrolysis of the 



