ON GALVANISM AND ELECTRICITY. }gl 



possible acid, as a borate or a fluate, be used instead of a 

 muriate for moistening the disks, the acid transferred cor- 

 responds with that of the salt employe;]. The salts with de- But no decom- 

 composable acids, as nitrates, sulphates, phosphates, ace- P°" ,able actd - 

 tates, &c, are in part decomposed by the combined effect 

 of the action of the pile, and of the attraction of the metal- 

 lic plates for their oxigen. This action appears to strengthen The evolution 

 the action of the pile, at the moment when it takes place, if •'" oxigen 



. . . . strengthens 



the moistening salt be an oximunate, or a nitrate, the oxigen the action of 



of which gives out caloric on entering into a more solid com- the P ile « 

 bination. But if it be a salt, the acid of which has what 

 Brugnatelli calls an oxigenizable radical, the energy is not 

 very different. This appears to prove, that it is owing to 

 the caloric separated from the oxigen, which, on entering 

 into the galvanic current, is partly transformed into electric 

 fluid. However, I have fancied 1 have observed a difference Influence of 

 of effect here, that is somewhat singular, and shows the '.^posing 

 great influence of disposing affinity : this is, that the energy 

 of the pile, in respect to what is called its charge, is increased 

 only when the substance subjected to its action is to be de- 

 composed, and that it is almost the same as with other salts, 

 when it is to be composed. We know, that in the first case, 

 namely when principles are to be separated by the direct 

 action of the electric fluid, this fluid, without altering its 

 nature, enters into combination with the principle separated, 

 which it converts into a gas: while in the second case, or 

 when it determines the union of principles that have been 

 separated, it is transformed into heat, simply to raise the 

 temperature: hence the caloric separated from the oxigen 

 will circulate either as electric fluid, or as heat, according as 

 the effect to be produced disposes it to assume or retain the 

 one or other of these modifications. It is not however a de- 

 termining attraction, that produces the elevation of tempera- 

 ture, of which I spoke in the commencement of my letter. 



The chemical action then does not heighten the activity of Chemical ac- 

 ~ ,, • . • • i • i tioji increases 



the pile, except as far as this action is accompanied with an that of the pile 



evolution of heat. only when heat 



I have said, that the circumstances I just mentioned in- ThTener'v of 



crease the energy of the pile momentarily: its activity af- thepy«dimi- 



terwerd diminishes, but less by its exhaustion than by the mihe ■ l e 



alteration 



