TRANSACTIONS OP THE SECTIONS. 397 



Decomposition is supposed to take place at both poles, and not 

 at all in the intermediate parts, which merely act as imperfect 

 conductors*. 



M. A. De la Rive experimented and wrote on this subject 

 in 1825. He says, those who refer the eiFect to the attraction 

 of the poles only express the fact, and do not explain it. He 

 thinks the results are due to a combination of the elements with 

 the electricities at the poles by virtue of a species of play of 

 affinities between the substances and the electricities. The 

 current at the positive pole unites with the hydrogen, combus- 

 tibles, metals and bases it may find there, leaving the oxygen 

 and the acids at liberty to escape : it passes across to the ne- 

 gative pole, on the surface of which it leaves the ponderable 

 bodies, entering itself into the metal, and passing away f . The 

 electricity at the negative pole does the same thing with oxygen, 

 chlorine, acids, &c., and carrying them across to the positive 

 pole, there leaves them. Thus half the elements on each side 

 are ejected by a species of superior affinity, and the other half 

 are brought from the opposite pole in combination with the 

 electricity of that pole. Successive decompositions and recom- 

 positions are not admitted by M. De la Rive. Decomposition 

 takes place at both poles, and only at the poles, and the inter- 

 vening parts of the humid conductor are themselves unaltered. 



Mr. Faraday contended that the experiments he had de- 

 scribed opposed generally all those views which referred electro- 

 chemical decomposition to the attractions and repulsions of the 

 poles. Thus, when the elements were evolved against air, the 

 poles as attractive agents were absent ; or if it be theoretically 

 said that the air then acted as poles, and attracted the element, 

 which, however, could not pass across it to the superior metallic 

 poles on the outside, then he quoted the water pole, where the 

 element might have gone to the metal, according to the theory, 

 but was found not to do so ; and as the evolved elements can 

 be made to appear against air, which is not a conductor, nor is 

 decomposed; or against water, which is a conductor, and can 

 be decomposed ; as well as against metals, which are excellent 

 conductors, but undecomposable, there appears but little reason 

 to consider the phaenomena generally as due to the attraction 

 or attractive powers of the latter, when used in the ordinary 

 way, since similar attractions can hardly be imagined in the 

 former instances. 



Mr. Faraday's view is, that the effect is produced by an in- 

 ternal corpuscular action, exerted according to the direction of 



* Precis Elcmentaire de Physique, 1824, torn. i. pp. 637, 641, 642, &c. 

 f Annales de Chimie, torn, xxviii. pp. 190, 200, 202. 



