1840.] The Galvanic Battery, 1175 



importance to observe, that the oxygen or other body must be in a 

 state of combination, and not only so, but combined in such proportions 

 as will constitute a substance capable of decomposition, since without 

 decomposition the transmission of a current cannot take place. The 

 presence of such a substance is therefore essential to the action of a 

 Voltaic circuit, and so intimate is the connection between its decompo- 

 sition and power of transmitting a current, that if the one be checked, 

 the other is checked also, and if the one be stopped entirely, the other 

 stops with it. No Voltaic Battery has been constructed in which the 

 chemical action is that only of combination ; decomposition is always 

 included, and is, according to Faraday's belief, an essential chemical 

 part. 



But as the quantity of electricity set in motion by the decomposi- 

 tion of a certain quantity of anelectrolytes or decomposable substance, 

 is definite in its action, and cannot by any means be increased beyond 

 a fixed limit, it is evident that the action of each cell of a Battery is not 

 to increase the quantity^ but the intensity of the current circulating. 

 A single pair of zinc and platinum plates throws as much electricity 

 into the form of a current by the oxidation of 32-5 grains of zinc, as 

 would be circulated by the same alteration of a thousand times that 

 quantity, or nearly 5ibs. of metal oxidised at the surfaces of the zinc 

 plates of a 1000 pairs, placed in regular Battery order, because at each 

 cell, the quantity of electricity is expended in producing the decompo- 

 sition of its equivalent of the exciting electrolyte, without which de- 

 composition, as was before remarked, the current could not circulate at 

 all. Hence then the action of each cell is to impel forward the quan- 

 tity of electricity due to the oxidation of the zinc in any one cell, and 

 thereby to exalt that peculiar property of the current, which we de- 

 signate intensity, without increasing the quantity beyond that due to 

 the zinc oxidised in that one cell. The waste of power in our com- 

 mon Batteries, in which the zinc of commerce is used, is so enormous 

 as to be almost incredible. Faraday asserts that the chemical action 

 of a grain of water upon four grains of zinc can evolve electricity 

 equal in quantity to that of a powerful thunder-storm, and that with 

 zinc and platinum wires one-eighteenth of an inch in diameter, and 

 about half an inch long, dipped in dilute sulphuric acid, so weak as not 

 to be sensibly sour to the tongue, more electricity will be evolved in 



