406 



that if water be subjected to the influence of the electric cur- 

 rent, no matter what the intensity or acting surface, the quan- 

 tity decomposed will be exactly proportionate to the quantity 

 of electricity which has passed. All this may be very true, 

 when applied to the voltaic influence, but, if so, the law seems 

 to individualize common electricity, and to dissever it from its 

 alleged identity with voltaic electricity. When we find two 

 estimates of an eff'ect to agree pretty well, while a third is forty- 

 two times greater than one, and thirty-eight times greater than 

 the other, it is plain there is a monstrous error somewhere ; 

 and hence, before we venture to draw any conclusion, it will 

 be necessary to investigate the grounds on which the discor- 

 dant opinion has been formed. This becomes the more neces- 

 sary, when it is recollected that the stronghold of those who 

 maintain the identity of the voltaic and electric agents is the 

 almost unlimited supply of the latter at a low intensity, which, 

 they affirm, can be brought into action during the exhibition 

 of any phenomenon caused by the former. 



Faraday has affirmed, as already observed, that one grain 

 of water, decomposed by four grains of zinc, can evolve elec- 

 tricity to an enormous amount, no less than 240 millions of 

 one-inch sparks. To test this, an experiment was made, in 

 which diluted sulphuric acid was made to act on a voltaic pair 

 consisting of four grains of zinc foil and a plate of platinum, 

 the metals being separately connected with a diff"erential elec- 

 trometer with insulated, detached, and moveable gold leaves. 

 The solution of the zinc occupied one minute and a half, and 

 during this period the gold leaves were rapidly approached 

 until they touched, and then rapidly withdrawn ; there was 

 not the slightest attraction or repulsion, although, according 

 to Faraday's estimate, the equivalent of 240 millions of one- 

 inch sparks was passing between them at the time. Yet, when 

 the same electrometer was subjected to the action of a voltaic 

 series, consisting of twenty pairs of three-quarter-inch plates, 

 both attraction and adhesion took place. 



