Resistance of Copper Sulphate in Glycerine. 



54b 



portion of the curve is evidently one to be avoided by any 

 person desiring to make up a solution to give a definite 

 resistance. The peaks correspond, in a general way, to the 

 discontinuities in the curves for solutions of other salts got by 



Curve III. 



: l I 



•02 



•04 -06 -08 '50 -\2 -14- -/6 



Gms. Copper Su/ph&te &dded to I ' gm. glycerine. 



Jones and his collaborators *, and attributed by them to the 

 differences in association and dissociation of the molecules 

 when the amount of the salts and water added to the 

 glycerine is varied. 



Glycerine solutions are hygroscopic and their resistances, 

 especially the higher values, vary slightly as they absorb 

 water. Accordingly, it is desirable to seal in the electrodes 

 when a fixed resistance is required ; while in the cape of 

 variable resistances, the rod carrying the movable electrode 

 may be made to slide in a hole in a rubber cork which forms 

 a fairly air-tight joint. The solutions have been found to 

 be very free from polarization, and the curves show that a 

 very wide range of resistance is obtainable. 



In conclusion, the writer wishes to thank Dr. Beatty, who 

 suggested this research, for his continued interest and advice 

 during its progress. 



* Loc, cit, 



