THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH 8BRIE8.] 



N 1 3 (92T 



JUNE 1921. 



LXXIX. The Dielectric Constants of Electrolytic Solutions.. 

 By R. T. Lattey, B.Sc, ALA.* 



I. 



THE values given by various observers for the change 

 in the dielectric constant produced by dissolving 

 electrolytes in water show considerable divergence. To 

 take the case of copper sulphate — Drude 16 ' 17 , Coolidge 13 , 

 and Palmer 47 were unable to distinguish any difference 

 between the dielectric constant of pure water and of 

 solutions of this salt, whereas Smale 52 asserts that a 

 0*05 normal solution has a dielectric constant 15'5 per 

 cent, greater than that of water. Now, according to the 

 Nernst-Thomson 56 rule, the dielectric constant of a solvent 

 is intimately connected with the degree of ionization of 

 an electrolytic solute ; and it is therefore of importance 

 that we should have a knowledge of the effect of the solute 

 on the dielectric constant of the solution. It seems to be 

 pretty generally assumed that this effect is to raise the 

 dielectric constant — a view which is supported by Smale's 

 experiments with aqueous solutions and by Walden's 60 

 experiments with non-aqueous solutions. The observations 

 of Drude 14 - 21 , Coolidge 13 , Eichenwald 25 , and Palmer 17 are 



* Communicated by the Author. 

 Phil. Mag. S. 0. Vol. 41. No. 246. June 192L 3 I 



