66 HISTORY OF GALVANISM. 



metal itself. The metallic solution was placed in 

 the bottom of a cylindrical jar, and a stratum of 

 water was carefully spread over it. A slip of the 

 same kind of metal that formed the solution was 

 then placed perpendicularly in both the fluids. 

 The upper part of the metal which was in the 

 water was oxidated, while the lower part in the 

 metallic solution had particles of the reduced metal 

 deposited upon it. The reduction of the oxide 

 was always expedited by whatever promoted the 

 Grotthas's oxidation of the upper part of the metal.* Ex- 

 ments'on periments of an analogous nature were performed 

 Son "**" ky Grotthus, on what he calls the arborization of 

 metals, which, like the circle of actions described 

 by Bucholtz, he attributes to a galvanic operation. 

 In these processes, however, there are two metals 

 concerned ; and he shows that the tree is formed 

 by successive portions of the dissolved oxide being 

 reduced and attached to the solid metal, which, in 

 its turn, becomes oxidated.f I have a little anti- 

 cipated the chronological order in the relation of 

 these last two sets of experiments, in order that 

 the account of the decomposition of the alkalies 

 and earths, which composes the third period of the 

 history of galvanism, might not be interrupted. 



* Ann. de Chim. Ixvi. 266. f Ibid. Ixiii. 5. 



