Absolute Quantity of Electricity in Matter. 433 



can be brought to bear on this point. To illustrate this I must 

 say a few words on the voltaic pile *. 



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 instrument, 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 substances, 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 continued by chemical action, and that the supply con- 

 stituting the current is almost entirely from that source. 



858. Those bodies which, being interposed between the 

 metals of the voltaic pile, render it active, are. all of them elec- 

 trolytes (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 trans- 

 mission of a current are so intimately connected, that one 

 cannot happen without the other. This I have shown abund- 

 antly in water, and numerous other cases (402. 476.). If, 

 then, a voltaic trough have its extremities connected by a de- 

 composing 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 decomposing or experimental cell, and 

 the acting cells, is simply this. In the former we urge the 

 current through, but it, apparently of necessity, is accom- 

 panied by decomposition : in the latter we cause decomposi- 

 tions by ordinary chemical actions, (which are, however, 

 themselves electrical,) and, as a consequence, have the electri- 

 cal current ; and as the decomposition dependent upon the cur- 



* By the term voltaic pile, I mean such apparatus or arrangement of 

 metals as up to this time have been called so, and which contain water, 

 brine, acids, or other aqueous solutions or decomposable substances (476.), 

 between their plates. Other kinds of electric apparatus may be hereafter 

 invented, and I hope to construct some not belonging to the class of in- 

 struments discovered by Volta. 



Third Series. Vol. 5. No. SO. Dec. 1834. 3 K 



