314 Cellulose 



neglected, or whether the incidental effect of the oxidant upon 

 the cellulose is negligible. This introduces the question of 

 verifying the product, finished with or without the oxidising or 

 bleaching treatment proposed, as a ' normal ' cellulose. Any 

 tests adopted must measure (i) the degree of resistance to 

 hydrolytic and oxidising treatments, and (2) the condition of 

 reactivity in regard to the formation of synthetical derivatives. 



In regard to the selection of alternatives, in either case 

 there is an obvious basis of criticism, the reactions involved 

 must be the simplest possible. Thus in regard to (i) pre- 

 ference may be given to treatments at ordinary temperatures, 

 i.e. avoiding the complications introduced by heat. This 

 would specially apply as a criticism of the specification of tests 

 for control of cotton raw material for nitro-cellulose manufac- 

 ture. Boiling with 3 p.ct. NaOH solution on the one hand, 

 and the alkaline oxidant (Cu(OH 2 ),as Fehling's solution) on the 

 other, are treatments involving complex and hitherto unde- 

 termined changes of the cellulose itself. That the specification 

 is justified by results is no counter-criticism of our present 

 argument. The specialists in this branch of scientific 

 technology will admit this; but it is a question for them 

 whether there are any grounds in this discussion for revising 

 their specification and basis of control. It only remains to 

 be said that of the numberless alternatives as between alkaline 

 and acid hydrolytic treatments and oxidising reactions, direct 

 or indirect, alkaline or acid, and the order of successive ap- 

 plications of these, the basis of selection should be relative 

 simplicity of the reactions involved. 



It is on this ground that we have generally adopted the 

 mercerising reaction, followed by treatment of the product with 

 carbon bisulphide, observations on the resulting xanthogenate 

 (viscose) and reversion to cellulose the whole cycle being 

 quantitatively followed in every particular as the most compre- 

 hensive diagnosis of any given cellulose, affording the fullest 



