126 Dr. Faraday’s Experimental Researches in Electricity. 
or 37°25 equivalents upon the whole; whilst twenty pairs lost 
2°53 each, or 50°6 in all; and forty pairs lost on an average 
2°21, or 88°4 altogether. In both these cases, therefore, in- 
crease of numbers had not been advantageous as to the effec- 
tive production of transferable chemical power from the whole 
quantity of chemical force active at the surfaces of excitation 
1120.). 
1153. But if I had. used a weaker acid or a worse con- 
ductor in the volta-electrometer, then the number of plates 
which would produce the most advantageous effect would 
have risen; or if I had used a better conductor than that 
really employed in the volta-electrometer, I might have re- 
duced the number even to one; as, for instance, when a thick 
wire is used to complete the circuit (865. &c.). And the 
cause of these variations is very evident, when it is considered 
that each successive plate ‘in the voltaic apparatus does not 
add anything to the quantity of transferable power or electri- 
city which the first plate can put into motion, provided a good 
conductor be present, but tends only to exalt the zntenszty of 
that quantity, so as to make it more able to overcome the ob- 
struction of bad conductors (994. 1158.). 
1154. Large or small plates*.—The advantageous use of 
large or small plates for electrolyzations will evidently depend 
upon the facility with which the transferable power or electri- 
city can pass. If in a particular case the most effectual num- 
ber of plates is known (1151.), then the addition of more zine 
would be most advantageously made in increasing the size of 
the plates, and not their number. At the same time, large 
increase in the size of the plates would raise in a small degree 
the most favourable number. 
1155. Large and small plates should not be used together 
in the same battery: the small ones occasion a loss of the 
power of the large ones, unless they be excited by an acid 
proportionably more powerful; for with a certain acid they 
cannot transmit the same portion of electricity in a given 
time which the same acid can evolve by action on the larger 
plates. 
1156. Simultaneous decompositions. When the number of 
plates in a battery much surpasses the most favourable pro- 
portion (1151—1153.), two or more decompositions may be 
effected simultaneously with advantage. ‘Thus my forty pairs 
of plates (1124.) produced in one volta-electrometer 22°8 
eubic inches of gas. Being recharged exactly in the same 
manner, they produced in each of two volta-electrometers 24 
* Gay-Lussac and Thenard, Recherches Physico-chimiques, tom. i. p. 29. 
