10 HISTORY OF GALVANISM. 



The deft, and The dearie fluid thus united to hidrog-en, is carried to tho 



hidrogen pals in- . . - - . ° . . 



vifibly to the otner point ct the wire, where, upon entering the oxidable 

 other point, conductor, it is difen^aeced in the form of hidrojrenous gas, if 



where the firft „ , , 4 . ** ? . . .,- r , ,. c 



is abforbed and Water be the medium ot communication ; it a folution or a rae- 



the latter be- tallic oxide be employed, it unites with the oxide, and reduces 



or tfYhf fluid lL The d ecompofition of water is therefore efrefted at the 



contain oxide, it zinc point alone, though the different gafes which compofe it 



reduces the me- are difengaged at each of the points : and this proexft will 

 tal and again , , • ' , 



forms water. continue even when the points terminate m two different por- 

 tions of water, as was difcovered by Mr. Davy, provided that 

 the glades are united by a conductor which is not oxidable. 

 Theory of the This may be confidered as a general explanation of the firft 

 ' fubject of inquiry ; we mull next proceed to mveftigate the na- 

 ture of the operation carried on in the body of the apparatus 

 itfelf. In the conftruction of the pile there are two points which 

 are eflential to its action; ]ft, That the electric fluid be difen- 

 gaged ; and, 2dly % That it be confined and carried forward in 

 one direction, fo as to be concentrated in the end of the appa- 

 The oxidation of rat us. The firft object is evidently attained by the oxidation 

 the zinc deve- Q p ^e z j nc or other ox jdable body employed. If both fides of 

 which decom- the zinc were oxidated, the electric fluid would indeed be li- 

 pofes the water, berated, but it would be immediately difperfed, and its effects 

 by the hidrogenj could not be obferved. As foon, however, as the electric mat- 

 ter is evolved, it is immediately attracted by the hidrogen, 

 which is at the fame time neceffarily generated in the fluid 

 and therefore which oxidates the metal, and it is by this means conveyed 

 paffes to the fil- acro f s t h e water ± fa e fi\ veY plate, when two metals are ufed; 

 fluid, and not or > i« other cafes, fimply to the oppofite furface of the oxidat- 

 thc reverb. j n g fubftance. The dectric fluid then enters the filver plate, 

 nex^oxidating anc * ' n ^ ant 'y palling on to the contiguous zinc plate, arrives at 

 furface adds to a fecond oxidating furface. The fame feries of events which 

 el^nTTncieaf's^^ ^ e " n defcribed is here repeated, except that the electric 

 the oxidation j fluid being in fome degree accumulated in the metallic plate, 

 is difengaged by the fecond oxidating furface in larger quan- 

 and this effeft tity, and in a more concentrated flate, than before. By pur- 

 withthTn umber ^ um g the fame train of operation*?, it is eafy to fee how the 

 of pairs. electric matter will continue to be accumulated in each fuccef- 



five pair of plates, until, by fuffieient repetition, it may be made 

 to exift in the zinc end of the pile in any afligned degree of 

 force. 



Having 



