118 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 



857. Intending hereafter to apply the results given in this and the preceding series 

 of Researches to a close investigation of the source of electricity in the voltaic in- 

 strument, I have refrained from forming any decided opinion on the subject ; and 

 without at all meaning to dismiss metallic contact, or the contact of dissimilar sub- 

 stances, being conductors, but not metallic, as if they had nothing to do with the 

 origin of the current, I still am fully of opinion with Davy, that it is at least con- 

 tinued by chemical action, and that the supply constituting the current is almost en- 

 tirely from that source. 



858. Those bodies which, being interposed between the metals of the voltaic pile, 

 render it active, are all of them electrolytes (476.) ; and it cannot but press upon the 

 attention of every one engaged in considering this subject, that in those bodies (so 

 essential to the pile) decomposition and the transmission of a current are so intimately 

 connected, that one cannot happen without the other. This I have shown abundantly 

 in water, and numerous other cases (402. 476.). If, then, a voltaic trough have its 

 extremities connected by a decomposing body, as water, we shall have a continuous 

 current through the apparatus ; and whilst it remains in this state may look at the 

 part where the acid is acting upon the plates, and that where the current is acting 

 upon the water, as the reciprocals of each other. In both parts we have the two 

 conditions inseparable in such bodies as these, namely, the passing of a current, and 

 decomposition ; and this is as true of the cells in the battery as of the water cell ; for 

 no voltaic battery has as yet been constructed in which the chemical action is only 

 that of combination : decomposition is always included, and is, I believe, an essential 

 chemical part. 



859. But the difference in the two parts of the connected battery, that is, the de- 

 composing or experimental cell, and the acting cells, is simply this. In the former 

 we urge the current through, but it, apparently of necessity, is accompanied by 

 decomposition : in the latter we cause decompositions by ordinary chemical actions, 

 (which are, however, themselves electrical,) and, as a consequence, have the electrical 

 current; and as the decomposition dependent upon the current is definite in the 

 former case, so is the current associated with the decomposition also definite in the 

 latter (862. &c.). 



860. Let us apply this in support of what I have surmised respecting the enormous 

 electric power of each particle or atom of matter (856.). I showed in a former series 

 of these Researches on the relation by measure of common and voltaic electricity, 

 that two wires, one of platina and one of zinc, each one eighteenth of an inch in dia- 

 meter, placed five sixteenths of an inch apart, and immersed to the depth of five 

 eighths of an inch in acid, consisting of one drop of oil of vitriol and four ounces of 

 distilled water at a temperature of about 60° Fahr., and connected at the other ex- 

 tremities by a copper wire eighteen feet long, and one eighteenth of an inch in thick- 

 ness, yielded as much electricity in little more than three seconds of time as a Leyden 

 battery charged by thirty turns of a very large and powerful plate electric machine 



