Manchester Memoirs, Vol. Ixv. (1921), No. 12 



11 



It is an interesting- fact that ferric hydroxide while soluble 

 in the calcium, strontium, and magnesium thiocyanate solu- 

 tions, all of which are cellulose solvents, is insoluble in the 

 potassium thiocyanate, and calcium chloride solutions of any 

 concentration, both the latter solutions being also non- 

 solvents for cellulose. 



Ao 



rs 



re 



os- 



o *- 



B . C*Iculh\ >» 

 C • Co bale ■! 



£.Fe-rric m 



TUT f'Z I-35- I'A- 

 ~~ ^/(Xr. °f Sol-uiion > 



M4T 



Fig. 5. 



Lead sulphate and tricalcium phosphate are also soluble 

 to a limited extent in the concentrated solution, while certain 

 water soluble salts such as sodium chloride and potassium 

 chromate are insoluble. In the light of the above facts, it is 

 evident that one of the main conditions of a cellulose solvent 

 is, that not onlv must the salt combine with water to form a 



