Effect of largeand smallPlates : Simultaneous Decompositions.127 
cubical inches. In the first experiment the whole consump- 
tion of zinc was 88"4 equivalents, and in the second only 
48°28 equivalents, for the whole of the water decomposed in 
both volta-electrometers. 
1157. But when the twenty pairs of four-inch plates (1129.) 
were tried in a similar manner, the results were in the oppo- 
site direction. With one volta-electrometer 52 cubic inches 
of gas were obtained; with two, only 14°6 cubic inches from 
each. The quantity of charge was not the same in both cases, 
though it was of the same strength ; but on rendering the re- 
sults comparative by reducing them to equivalents (1126.), 
+t was found that the consumption of metal in the first case 
was 74, and in the second case 97, equivalents for the whole 
of the water decomposed. These results of course depend 
upon the same circumstances of retardation, &c., which have 
been referred to in speaking of the proper number of plates 
(1151.). 
1158. That the transferring, or, as it is usually called, con- 
ducting, power of an electrolyte which is to be decomposed, 
or other interposed body, should be rendered as good as pos- 
sible*, is very evident (1020. 1120.). With a perfectly good 
conductor and a good battery, nearly all the electricity is 
passed, i. e. nearly all the chemical power becomes transfer- 
able, even with a single pair of plates (867.). With an inter-~ 
posed non-conductor none of the chemical power becomes 
transferable. With an imperfect conductor more or less of 
the chemical power becomes transferable as the circumstances 
favouring the transfer of forces across the imperfect conductor 
are exalted or diminished: these circumstances are, actual 
increase or improvement of the conducting power, enlarge- 
ment of the electrodes, approximation of the electrodes, and 
increased intensity of the passing current. 
1159. The introduction of common spring water in place 
of one of the volta-electrometers used with twenty pairs of 
four-inch plates (1156.) caused such obstruction as not to al- 
low one fifteenth of the transferable force to pass which would 
have circulated without it. Thus fourteen fifteenths of the 
available force of the battery were destroyed, being converted 
into local force, (which was rendered evident by the evolution 
of gas from the zines,) and yet the platina electrodes in the 
water were three inches long, nearly an inch wide, and not 
a quarter of an inch apart. 
1160. These points, i. e. the increase of conducting power, 
* Gay-Lussac and Thenard, Recherches Physico-chimiques, tom. i. pp. 13, 
15, 22. 
