428 Prof. A. de la Rive's Memoir oj 



or less facility or rapidity with which this polarization, necessary 

 for the transmission of electricity, takes place in them. Then, 

 passing- from this to the analysis of the different modes in which 

 electrical discharges take place, some obscure, others luminous, 

 some electrolytic (that is to say, accompanied by the chemical 

 decomposition of the conducting body), others disruptive (that 

 is to say, effected by the mechanical disjunction of the particles 

 of the interposed substance), he applied himself more particu- 

 larly to the study of the various forms displayed by the electric 

 spark in more or less rarefied gases. I should never have done 

 if I were to attempt to explain all the experiments which he 

 made to elucidate these different points and to arrive at an idea 

 of the actual nature of the electric current. The identity of the 

 current, whatever may be its origin, — that its production is due 

 to polar forces which may exert a transverse action, as is the case 

 in electrodynamical phenomena, — that these polar forces emanate 

 from contiguous particles; such are the principles which Faraday 

 endeavoured to establish as the consequences of his experimental 

 researches, at the same time that he rejected the idea of actions 

 at a distance, referring all electrical manifestations to the presence 

 of ponderable matter. 



Whether or not we completely admit all Faraday's ideas, it is 

 impossible not to acknowledge the immense advance which he 

 caused the theories of electricity to make, either by demonstra- 

 ting by experiment the falsity of certain conceptions generally 

 accepted up to his time, or by opening up perfectly new points 

 of ^view as to the actual nature of electrical phenomena. We 

 have just had the proof of this in the consequences to which he 

 was led by his investigations on statical induction. His disco- 

 veries in electrodynamical induction have had still more import- 

 ant consequences, by introducing the notion of mechanical 

 movement into the essence of electrical movement, and thus en- 

 abling Weber to combine, in an equally ingenious and satisfac- 

 tory manner, the mechanical phenomena of electrodynamics, dis- 

 covered by Ampere, with the electrical phenomena due to me-' 

 chanical movement, discovered by Faraday. 



Ampere and Faraday, — two names which will always be united 

 by the intimate relation of their works to the history of the science 

 of electricity, in which they have opened such new and vast hori- 

 zons; and yet minds as dissimilar in their mode of proceeding 

 as similar in the power of their genius. Both eminently en- 

 dowed with that faculty of divination which generates great dis- 

 coveries, but one of them, Faraday, arriving at them by impres- 

 sion, by a kind of instinct which never deceived him, — the other, 

 Ampere, advancing with a more certain step, having as his 

 instrument those calculations which he handled with such re- 



