Michael Faraday, his Life and Works. 159 
decomposition of an equal quantity of the same, or of a chem- 
ically equivalent quantity of some other body. He is thus led 
to pay attention to the theory of the pile, and to recognize that 
the power of this apparatus originates in chemical action, and 
not in the contact of two heterogeneous metals—a contact 
which is not necessary either, to produce a spark or to cause a 
chemical decomposition. ; 
He establishes in the first place, that, either to effect a de- 
composition or to produce a spark, a plate of zinc immersed in 
. _ acidulated water is sufficient without its being necessary to bring 
the zinc into contact with any other metal. He shows that in 
every pile the presence of an electrolyte (that is to say, a liquid 
susceptible of being decomposed) is indispensable for the evolu- 
tion of electricity, Then, distinguishing in the electricity gen- 
erated the intensity (or the tension) and the quantity, he studies 
the circumstances, depending either on the nature of the chem- 
ical action or the number of voltaic pairs associated, which 
exert an influence on these two characters of the current. In 
a word, he establishes such a correlation between that which 
occurs in the interior of a pile and that which takes place in the 
| electrolyte interposed between the poles of this pile, that it 
is impossible not to admit (with him) that electrolytic de- 
composition is nothing but a form of chemical affinity trans- 
ferred from the pile into the electrolyte decomposed. ; é 
_-. Wishing to obtain an idea of the quantity of electricity which 
"18 associated with the particles of which matter is composed, he 
endeavors to estimate that which is necessary for the decompo- 
sition ofa grain of water, regarding it, as he is justified in doing, 
a8 equivalent to that produced by the direct chemical action (of 
the acidulated water upon the zinc) which decomposes this grain 
: _ of water, He arrives at this incredible result—namely, that this 
quantity of electricity, appreciated by the heat evolved by it in 
ane a fine platinum wire, is superior to that manifested 
in 
chemical action that resides the origin of the evolution of elec- 
adherent of the chemical theory, he had just attacked the ques- 
. 
