254 M. Viard on the Electro-chemical Deportment of Oxygen. 



All these experiments, therefore, confirm and generalize the 

 results before obtained with a zinc battery, by Adie, Gassiot, 

 Joule, De la Rive, and still earlier by Cuvier and Biot, under 

 very different circumstances. 



Now that we have verified the influence of oxygen in the bat- 

 teries, we have to examine its special influence upon each of the 

 plates. 



This question is easily solved experimentally. It suffices in 

 the apparatus with tubes, before used (fig. 1), to close the tubes 

 by bladders ; in one apparatus to fill the two with the same elec- 

 trolyte at the same degree of oxidation ; in the other apparatus 

 to fill them with the same electrolyte, but at different states of 

 oxidation ; and lastly, to observe the currents which are pro- 

 duced by changing the plates from one apparatus to the other, 

 and thus successively, on each plate, replacing the aerated liquid 

 by the boiled liquid, and reciprocally. 



Some of the results obtained are shown by the following table, 

 where, for greater simplicity, the least oxidable plate is supposed 

 always to be on the right, so that ba indicates that the aerated 

 liquid is on the side of the least oxidable plate, and ab the con- 

 trary disposition. 



