130 Messrs. Gee and Holden on 



pass more easily from the lesser to the greater electrode, and 

 vice versa with large E.M.F.'s. This difference, he says, exists 

 after the influences of polarization and chemical transition 

 resistance are allowed for, meaning by the latter term a re- 

 sistance due to the products of electrolysis. We have been 

 at some trouble to examine the experiments and reasoning 

 upon which the above conclusion is based, and have arrived 

 at the opinion that they are equally open to criticism; his 

 results and theory being, however, very interesting and repre- 

 senting a large amount of work, it will hence be desirable to 

 notice them at some length, especially as his pamphlet is not 

 readily accessible in England. 



In order to eliminate as much as possible changes in the 

 electrolyte caused by the passage of the current, momentary 

 currents from an induction-coil were used throughout the 

 greater part of his work, his object being a study of the 

 nature and causes of irreciprocal conduction, with unequal- 

 sized electrodes, in electrolytes. For this purpose, applying 

 a momentary E.M.F.tothe voltameter, he desires to measure: — 

 (a) The quantity of electricity which is sent through the ' 

 voltameter by this E.M.F., and (b) the polarization which 

 opposes its passage. 



Fig. 2 shows the essential parts of the arrangement used 

 with induced currents. V is the voltameter with a platinum 

 plate and a platinum Wollaston's point as electrodes. In 

 circuit with it are a dead-beat Wiedemann's galvanometer 

 (G) and the secondary coil (S) of an induction-coil, of which 

 P is the primary coil in circuit with a battery. By changing 

 the distance of S from P ( = <#)> the E.M.F. of the induced 

 current can be varied. The experiments were conducted 

 somewhat as follows : — By opening the primary circuit a 

 quantity of electricity ( = qi) is sent through the voltameter, 

 and the kick ( = k l ) on G is noted. If the deflection does not 

 return exactly to zero, but goes on the other side of it, this 

 negative deflection ( = ei) is observed, and afterwards, in dis- 

 cussing the possible causes of irreciprocal conduction, is taken 

 as a measure of the polarization opposing the passage of q^. 

 The same induced E.M.F. is now, by reversing the voltameter 

 terminals, applied in the opposite direction. Let k 2 and e 2 

 be the deflections now obtained, and suppose that q 2 is the 

 quantity of electricity sent through the voltameter in this 

 direction of the current. The distance of S from P is now 

 altered, generally by 5 millim. at a time, and at each new 

 position the above procedure is repeated, giving values of k x 

 and k 2 for each value of x. He finds that k x and k 2 are 

 enerally different, but for one value of x they are equal; for 



