124 Dr. Faraday’s Experimental Researches in Electricity. 
after the fourth time with the same charge, the loss was from 
3°26 to 4°47 equivalents per plate; the average being 3°7 equi- 
valents. The first time the forty pair of plates (1124.) were 
_ used, the loss at each plate was only 1°65 equivalent; but 
afterwards it became 2°16, 2°17, 2°52. The first time twenty 
pair of four-inch plates in porcelain troughs were used, they 
lost, per plate, only 3°7 equivalents; but after that, the loss 
was 5°25, 5°36, 5°9 equivalents. Yet in all these cases the 
zincs had been well cleaned from adhering copper, &c., before 
each trial of power. 
1147. With the rolled zinc the fall in force soon appeared 
to become constant, i. e. to proceed no further. But with the 
cast zinc plates belonging to the porcelain troughs, it appeared 
to continue, until at last, with the same charge, each plate lost 
above twice as much zinc for a given amount of action as at 
first. These troughs were, however, so irregular that I could 
not always determine the circumstances affecting the amount 
of electrolytic action. 
1148. Vicinity of the copper and zinc.—The importance of 
this point in the construction of voltaic arrangements, and the 
greater power, as to immediate action, which is obtained when 
the zinc and copper surfaces are near to each other than when 
removed further apart, are well known. I find that the power 
is not only greater on the instant, but also that the sum of 
transferable power, in relation to the whole sum of chemical 
action at the plates, is much increased. The cause of this gain 
is very evident. Whatever tends to retard the circulation of 
the transferable force, (i. e. the electricity, ) diminishes the pro- 
portion of such force, and increases the proportion of that 
which is local (996. 1120.). Now the liquid in the cells pos- 
sesses this retarding power, and therefore acts injuriously, in 
greater or less proportion, according to the quantity of it be- 
tween the zinc and copper plates, i.e. according to the di- 
stances between their surfaces. A trough, therefore, in which 
the plates are only half the distance asunder at which they are 
placed in another, will produce more transferable, and less 
local, force than the latter; and thus, because the electrolyte 
in the cells can transmit the current more readily, both the 
intensity and quantity of electricity is increased for a given 
consumption of zinc. To this circumstance mainly I attribute 
the superiority of the trough I have described (1134.). 
1149. The superiority of double coppers over single plates 
also depends in part upon diminishing the resistance offered 
by the electrolyte between the metals. For, in fact, with dou- 
ble coppers the sectional area of the interposed acid becomes 
nearly double that with single coppers, and therefore it more 
