Oxidation of the Zinc the Source of Electricity. 129 



current, the other is invariable in its concomitant production 

 and its relation to it. 



924. Consider, then, water as an electrolyte and also as an 

 oxidizing body. The attraction of the zinc for the oxygen 

 is greater under the circumstances, than that of the oxy- 

 gen for the hydrogen; but in combining with it, it tends to 

 throw into circulation a current of electricity in a certain di- 

 rection. This direction is consistent (as is found by innumer- 

 able experiments) with the transfer of the hydrogen from the 

 zinc towards the platina, and the transfer in the opposite di- 

 rection of fresh oxygen from the platina towards the zinc ; so 

 that the current can pass in that one line, and, whilst it passes, 

 can consist with and favour the renewal of the conditions upon 

 the surface of the zinc, which at first determined both the 

 combination and [the] circulation. Hence the continuance of 

 the action there, and the continuation of the current. It there- 

 fore appears quite as essential that there should be an elec- 

 trolyte in the circuit, in order that the action may be trans- 

 ferred forward, in a certain constant direction, as that there 

 should be an oxidizing or other body capable of acting directly 

 on the metal ; and it also appears to be essential that these two 

 should merge into one, or that the principle directly active 

 on the metal by chemical action should be one of the ions of 

 the electrolyte used. Whether the voltaic arrangement be 

 excited by solution of acids, or alkalies, or sulphurets, or by 

 fused substances (476.), this principle has always hitherto, as 

 far as I am aware, been an anion (943.) ; and I anticipate, 

 from a consideration of the principles of electric action, that 

 it must of necessity be one of that class of bodies. 



925. If the action of the sulphuric acid used in the voltaic 

 circuit be considered, it will be found incompetent to pro- 

 duce any sensible portion of the electricity of the current by 

 its combination with the oxide formed, for this simple reason, 

 it is deficient in a most essential condition; it forms no part 

 of an electrolyte, nor is it in relation with any other body 

 present in the solution which will permit of the mutual transfer 

 of the particles and the consequent transfer of the electricity. 

 It is true, that as the plane at which the acid is dissolving the 

 oxide of zinc formed by the action of the water, is in con- 

 tact with the metal zinc, there seems no difficulty in consider- 

 ing how the oxide there could communicate an electrical state, 

 proportionate to its own chemical action on the acid, to the 

 metal, which is a conductor without decomposition. But on 

 the side of the acid there is no substance to complete the cir- 

 cuit : the water, as water, cannot conduct it, or at least only 

 so small a proportion that it is merely an incidental and al- 



Third Series, Vol. 6. No. 32. Feb. 1835. S 



