adduced by Prof. Faraday in support ofDe la Rive's Theory. 539 



tendency exists even in one pair alone, it is not intelligible how 

 it happens that the two electricities do not avoid passing the 

 damp conductor, the metallic way, which is so much more 

 conductive, being open to them. If, on the other hand, it be ad- 

 mitted that that tendency exists solely in the complex electro- 

 motor, then it is not intelligible how such a property arises in 

 it, if the elements of which it is formed (which are also so 

 many electromotors) are all without it. And to him who might 

 have objected to such an argument, that the greater part of 

 the two electric principles takes the metallic way to go to 

 neutralize itself, and that adding pairs to pairs the tension 

 increases, because the quantity which can pass through the 

 electromotor is less; — to him who, 1 say, might have thus ob- 

 jected, I recalled the fact that the alternations of moist and 

 metallic conductors diminish certainly the quantity of electri- 

 city which in a given time passes through the voltaic appa- 

 ratus, but do not alter the tension. 



I asked, in the second place, why the least indication may 

 not be had of such currents in a direction contrary to the 

 usual one. And finally, I found it difficult to be admitted 

 that the two electric principles tend to retrocede in the pile 

 in order to neutralize each other, whilst the virtue of the pile 

 consists, on the contrary, in the tendency to accumidate one of 

 such principles at the positive pole, and the other at the 

 negative. (§ XXXV.) 



The examination instituted by me respecting this manner 

 of explaining the effects of the pile was not limited to the 

 preceding abstract considerations, but was pursued also with 

 experiments. If the tension of a pile is, as M. de la Rive 

 says, relative to the greater or less difficulty which the pile 

 itself opposes to the passage of the electricity, it will be suf- 

 ficient, I said, to render the passage of the electric through 

 the electromotor more difficult, to see the tension at the poles 

 augmented ; and therefore, after having watched the tension 

 of a couronnc de iasses, I disposed the pairs in other cups, so 

 much more ample than the first, that the liquid stratum (which 

 was, as in the first apparatus, rain water) interposed between 

 each pair was about six times greater; and although here the 

 resistance might be much greater which the electricity must 

 encounter in moving itself in the apparatus, yet the tension 

 was found to be not at all increased. 



In the work of M. de la Rive no reply is given either to 

 the experiments or to the reasonings here above-mentioned, 

 with which I intended to prove the insufficiency of his theory 

 in explaining the phaenomena of the complex electromotors. 



