﻿214 M. W. von Bezold's Investigations on the Electrophorus. 



p 1 + (2m- 1) w 2 1 + {2m— l)v 2 



n-\-p~~ 1—w 2 1— v 2 



+ 



l + (2m-l)w 2 ' l + (2m-l)v 2 

 2m(?j 2 -w 2 ) 



{l + (2m-l)y 2 }(l-w; 2 ) + (l-v 2 ){l+(2m-l)M; 2 } 



2m sin 2 {$ — (pi) 

 l+(2m-l)i; 2 +cos 2 (^-^ 1 ){l + (2m-l)^ 2 } 



m sin 2 (</> — c^) 



or 



l + (2m — l)v 2 — -msin 2 (<£•— </>J 

 mtan 2 (<£ — ^ t ) 



1 -f (2m - 1 )zu 2 -f ??z tan 2 (0 - &) 

 These expressions may conveniently be put in the form 



p __■ m 



sm 2 (<£ — <k) sin 2 (0 + ^i) 



or 



, 2m -1 



n+T? _ sm g (<ft — gj sin 2 (eft -f cftj 

 j3 m 



For a given value of m (as, for instance, when there are four 

 plates) this expression for the degree of polarization may be 



readily calculated; and, as we have seen, -^— - expresses the 



proportion of polarized light in the incident beam when the 

 light is completely depolarized by the plates. 



XXVIII. Investigations on the Electrophorus, 

 By W. von Bezold*. 



SOME time ago Professor Beetz called my attention, in con- 

 versation, to the circumstance that the experiments on the 

 electrical deportment of an electrophorus-cake do not always 

 succeed with that certainty which might be expected from an 

 apparatus whose functions are supposed to he thoroughly known. 

 As just at that time I was engaged on my recently published 

 experiments on the electrical discharge, and as I had at hand 

 the sensitive mixture of powdered red lead and sulphur, it at 



* Translated from a separate impression, communicated by the Author, 

 of a paper read before the Royal Bavarian Academy of Sciences, July 2, 

 1.870. 



