4 H. E. Williams — Action of Neutral Salts on Cellulose 



With the exception of the solutions of calcium chloride, 

 and potassium-manganese thiocyanate K 2 Mn[CNS] 4 , all 

 these solutions were found to be cellulose solvents at the 

 particular boiling- point concentration and viscosity at which 

 the curve crosses into the area marked " cellulose solvent 

 area." 



The two exceptions mentioned above were at first difficult 

 to explain, and it was realised that there was at least another 

 factor to be brought to light before the necessary physical 

 constants for a cellulose solvent could be established. 



170 

 1 60 



ISO 



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14-0 



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 140 

 (10 



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Fig. 1. 



A consideration of this question suggested the following 

 line of reasoning. If one of the necessary preliminary condi- 

 tions before the cellulose dissolves is the hydration of the 

 cellulose, it is evident that if the water present in the aqueous 

 solution is attached to the salt with too great an affinity, it 

 will not hydrate the cellulose, but on the contrary will tend to 

 dehydrate it ; and no solution of the cellulose can result, 

 although the concentration and viscosity conditions are 

 fulfilled. 



In order to test this point the heat of dilution of these 

 aqueous salt solutions was determined at different concentra- 



