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



This table evidently shows that, for the four elements therein 

 contained, the intensity of the current increases with the quan- 

 tity of oxygen dissolved. 



The plates and liquids were varied in many ways, as may be 

 seen from the following table ; the results, however, were always 

 similar. No exception occurred, except with a battery of zinc 

 and iron in presence of dilute sulphuric acid, which, on account 

 of the abundant disengagement of hydrogen which then always 

 takes place, might have been easily foreseen. We shall after- 

 wards see how it is possible, even in this case, to verify the influ- 

 ence of oxygen. 



It was found impossible entirely to expel atmospheric air from 

 the liquids used in these experiments ; consequently, other ex- 

 periments were made, in order to ascertain to what degree the 

 current could be enfeebled by expelling as much oxygen as 

 possible. 



The plates of the elements were introduced into glass bells 



