532 Prof. Marianini's Examination of an E.rpcrimait 



sition a proof of tlie persuasion Avhich M. de la Rive begins 

 to entertain that his tlieory is not sufficient to explain the 

 phasnomena of the electromotors, if my experiments are true; 

 though, if Dr. Fusinieri would do them the honour to repeat 

 them, I doubt not that he would quickly be persuaded that 

 that modification is not sufficient for the theory; but it would 

 be necessary to add, that sometimes the electrization is in an 

 inverse ratio to the force of the chemical action, that is, to the 

 energy of the cause from which it is pretended to be derived. 

 But we are here at a point of my memoir which M. de la 

 Rive discusses in his Recherches, p. 125. 



XI. In describing the experiment of which I have now 

 spoken, M. de la Rive remarked that these plates of gold and 

 pure platina, immersed in the pure nitric acid, produce no 

 current whatever: and I said I had obtained the same phae- 

 nomena with the nitric acid as with the acid itself mixed with 

 a little hydrochloric acid, except that the galvanometric devi- 

 ations were somewhat less. Now, however, M. de la Rive 

 repeats the same thing ; that is, the not having obtained a simi- 

 lar current in making use of the pure nitric acid; and Signor 

 Fusinieri rather inclines to believe in the result of De la Rive, 

 having himself made the experiment with another scientific 

 man; and he thinks the observation just, which the same 

 Genevan physicist then adds, namely, that as I experimented 

 in Venice, it was a matter of difficulty that the nitric acid 

 should be entirely free from hydrochloric. And here it vexes 

 nie that I must point out to Signor Fusinieri that this diffi- 

 culty also presented itself to me, as is seen in the same page 

 in which I speak of this experiment; and not only did I see 

 the objection, but also removed it, by proving that by leaving 

 the nitric acid exposed for a long time to the Venetian air, 

 instead of acquiring to a much greater degree the aptitude to 

 cause that current, it went on losing it ; that is, on the con- 

 trary, it went on losing the power of altering to positive the 

 relative electromotive faculty of the platina and the gold so 

 far as to acquire the opposite property. (§ XXVI.) 



But there is yet more. Is it then true that there is that 

 difference in the fact Sy which Dr. Fusinieri remarks in this 

 proposition, namely, that De la Rive may not have seen in 

 immersing the gold and the platina in the nitric acid, the small 

 electric currents seen by me? And do we not read at the 

 eleventh page of his Rccherches, that in the act of immersing 

 that pair in the nitric acid there are seen slight galvanometric 

 deviations? " Du moins (these are his own wordsj le leger 

 courant que 1' on aper^oit au premier moment de I'immersion, 

 n'est pas plus fort que celui qui a lieu quand on se sert de 



