236 Intelligence and Miscellaneous Articles. 



stinguished philosophers as Messrs. Nobili and Marianini have de- 

 voted so much time to researches of so little general interest, and in 

 which it is so difficult to arrive at any precise and well-determined 

 result, and we even regret that they have done so. 



" In the memoir which we have cited above, {Comparison, S^c.) and 

 in a subsequent note, (Bibl. Univ. vol. xxxvii. p. 174,) M. Nobili 

 had cited several remarkable experiments on the development of elec- 

 tric currents by chemical action, and on the laws of this development. 

 He had placed beyond doubt the fact, disputed by Davy, of the 

 production of electrical currents by chemical action, and had shown 

 this production, in the case of simple solutions and double decom- 

 positions, as well as in the others. He had found no relation be- 

 tween the intensity of the currents obtained, and the intensity of the 

 chemical action, or the electric nature of the combined elements. 

 But having obtained sensible currents by applying heat to liquid or 

 humid bodies (such as moistened clay), he had thence concluded 

 that the electric currents developed in chemical action, are owing to 

 the heat which always accompanies it. Pursuing this idea, he 

 developed it more completely in a memoir, entitled ' On the Nature 

 of Electric Currents.' {Bibl. Univ. vol. xxxvii. p. 118.) In this 

 paper, the author successively passes under review the currents 

 which take place without chemical action, or the thermo-electric 

 currents, and those which are accompanied by chemical action, or the 

 hydro-electric currents. While occupying himself with the first, he 

 carefully studies the case when the circuit contains only a single 

 metal, that in which it contains two, that in which the circuit is hu- 

 mid, that in which it is mixed : in these two last cases, the current 

 appears to him to proceed always from the hot to the cold part ; in 

 the two first this law appears to suffer exceptions. In the examina- 

 tion which he makes of the electric currents, M. Nobili finds also 

 that the electric effects follow the course of the heat, more sensibly 

 in the cases in which one of the elements is solid, because the heat is 

 concentrated in it, than in the case when both are liquid, because the 

 heat is there disseminated. Summing together all the proofs of 

 the identity of caloric and electricity, he finally arrives at the conclu- 

 sion, that the electric current is only caloric in motion. The inverse 

 conclusion might with equal reason have been arrived at, that caloric 

 is only electricity in motion ; the truth isiprobably neither in one nor 

 the other of these two identities, round which philosophers have, as it 

 were, for a long time revolved. Singular weakness of the human 

 mind, which, because effects resemble each other, absolutely requires 

 that one be the cause, the other be the effect, as if they could not 

 both depend on a more general cause common to both 1 



Whatever be the judgement awarded respecting the merit of the 

 theory which we have just called to mind, the memoir of M. Nobili 

 will remain not less remarkable, from the curious facts with which it 

 has enriched science. Thenceforward, the subject of thermo-elec- 

 tric currents never ceased to occupy the learned Italian : he espe- 

 cially succeeded in making the thermo-electric pile the most sen- 

 sible of thermoscopic instruments. His first attempts of this kind ar« 



