1835.] Philosophical Transactions for 1834. 305 



electrolyte without relation to the quantity of electricity passed, the 

 decomposition of the electrolyte being produced, if the intensity is too 

 high. If this be confirmed, then we may arrange matters so that 

 the same quantity of electricity may pass in the same time into the 

 same decomposing body, in the same state, and yet differ in intensity, 

 decomposing in one case, and in the other not. 



III. Voltaic Battery. — From the principles laid down, it is 

 evident that the quantity of electricity in the current cannot be 

 increased by multiplying the quantity of metal oxidized ; a single 

 pair of plates, throwing as much electricity into the form of a cur- 

 rent, by the oxidation of 32*5 grs. of zinc as would be produced by 

 increasing the quantity of oxidized metal a thousand times. For the 

 action in each cell is not to increase the quantity set in motion in 

 any one cell, but to assist in urging that quantity forward, and in 

 this manner, the intensity is increased, without affecting the 

 quantity, beyond what is proportionate to the zinc oxidized in any 

 single cell of the series. Ten pairs of amalgamated zinc and platinum 

 plates, when acted upon by sulphuric acid, produced such a quantity 

 of gas as to prove that just as much electricity, and no more, had 

 passed through the series of ten pairs of plates, as had been trans- 

 mitted through or would have been put in motion by any single pair, 

 notwithstanding the consumption of ten times the quantity of zinc. 

 All these facts tend to shew that the act of decomposition opposes a 

 certain obstruction to the passage of the electric current, and that 

 this opposing force is overcome in proportion to the intensity of the 

 decomposing current. When ordinary zinc is used in a voltaic pile, the 

 waste of power is very great, for 3^ ounces of zinc, properly oxidized, 

 can circulate a current capable of decomposing nearly an ounce of 

 water, and of evolving 2400 cubic inches of hydrogen. This waste, 

 however, is greater with common zinc than with the pure metal, for, 

 when common zinc is acted upon by dilute sulphuric acid, portions 

 of copper, lead, cadmium, are set free on its surface, and form small 

 but active voltaic circles, which act apparently on the zinc surface, 

 but, in reality, upon those accidental metals. This effect is removed 

 by employing amalgamated zinc plates, which afford the full equiva- 

 lent of electricity for the oxidation of a certain quantity of zinc, but 

 are active only when the electrodes are connected. This improve- 

 ment in the voltaic battery is of great importance, for effects of 

 deecomposition can now be obtained with ten pairs of plates, which 

 formerly required 500 or 1000 pairs of plates. Dr. Faraday con- 

 ceives that in further improving the battery, plates of platinum or 

 silver may very likely be used instead of- copper, in order to avoid 

 the occasional solution of the copper, and its precipitation on the zinc. 

 IV. Resistance of Electrolytes to Electrolytic Action. — By 

 interposing a platinum plate, and adding sulphuric acid to a pair of 

 zinc and platinum plates, the current was completely stopped, by 

 requiring it to decompose water, and evolve both its elements before 

 it should pass. The same effect almost was produced when two pairs 

 of plates were used, and one interposed plate. But, in the case of 

 three pairs of plates, a current was induced which passed an inter- 

 posed platinum plate, but was stopped by two. The current origi- 

 nated by four pairs of plates was also obstructed by two interposed 

 vol. i. x 



