Resistance of Electrolytes at High Frequencies. 543 



observations were taken with the galvanometer shunted 300 

 times. The slope of the curve (left) is nearly 10 galvanometer 

 divisions per ohm. In the balance method, the galvanometer 

 being unshunted, one galvanometer division would clearly 

 correspond to^J^Xj 1 ^ or 3xl0 -4 ohm. In other words, 

 in the measurement of a resistance of about 60 ohms an 

 accuracy of 5 parts per million might be reached. For 

 higher resistances the error would be less, but the method 

 fails, of course, when the crest of the curve is reached. 



§ 10. Fig. 6 indicates that, when the resistance R (fig. 4) is 

 increased sufficiently, the anode current in the valve-circuit 



commences to decrease regularly. 



Eg. 



Although the relation 



:do 



100 





Cms. I 2 3 4 5 6 7 



between the anode current and R is not linear, it is, of 

 course, clear that high resistances can be measured in 

 much the same way as that described in § 9 for the smaller 

 ones. 



This method was therefore employed to investigate the 

 high frequency resistances of glycerine solutions of: copper 

 sulphate. Gilmour *, who investigated these solutions, found 

 that the specific resistance (for D.C.) varied irregularly with 

 the concentration over a certain range ; Jones and others have 

 described similar effects in other glycerine solutions. It is, 

 of course, of some interest to determine whether these 

 irregularities reproduce themselves at high frequencies. 



* Phil. Mao., March 1921. 



