332 SCIENCE PROGRESS 



The researches which led to the establishment of Faraday's 

 law, of course, aie classic. Thp followingf statement, made in 

 paragraphs 254, 255 and 260, embodies practically all thai ^n to 

 said even now, with any degree of conviction, of our knowledge 

 of the process of electrolysis : 



254. " Passing to the consideration of electrochemical decom- 

 position, it appears to me that the effect is produced by an 

 internal corpuscular action exerted according to the direction of 

 the electric current and that it is due to a force either superadded 

 to or giving direction to the ordinary chemical affinity of the bodies 

 present. The body under decomposition may be considered as 

 a mass of acting particles, all those which are included in the 

 course of the electric current contributing to the final effect ; 

 and it is because the ordinary chemical affinity is relieved, 

 weakened or partly neutralised by the influence of the electric 

 current in one direction parallel to the course of the latter and 

 strengthened or added to in the opposite direction, that the 

 combining particles have a tendency to pass in opposite courses." 



255. " In this view the effect is considered as essentially 

 dependent upon the mutual chemical affinity of the particles of 

 opposite kinds. . . ." 



260. " I suppose that the effects are due to a modification, by 

 the electric current, of the chemical affinity of the particles 

 through or by which that current is passing, giving them the 

 power of acting more forcibly in one direction than in another 

 and consequently making them travel, by a series of successive 

 decompositions and recompositions, in opposite directions and 

 finally causing their expulsion or exclusion at the boundaries of 

 the body under decomposition, in the direction of the current. . . ." 



The discussion " On the source of power in the voltaic pile," 

 in which the contact hypothesis is discarded by Faraday, is one 

 that deserves renewed attention at the present time. Owing to 

 the fact that Lord Kelvin's great influence was exerted in favour 

 of direct contact action, the explanation has regained favour — 

 but it is very doubtful whether the arguments that have been put 

 forward in support of this view are valid : at least they require 

 reconsideration. But physicists are now so much concerned 

 with metaphysics that fundamental problems in electro- 

 chemistry appear no longer to interest them. The publication 

 of Faraday's early memoirs may serve, in some measure, to 

 redeem the situation ; sometimes in set words but always 

 implicitly he was an advocate of the doctrine that truth is the 

 one possible foundation of science. 



