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XX. An Account of some Galvanic Combinations, formed by the 
Arrangement of single metallic Plates and Fluids, analogous 
to the new Galvanic Apparatus of Mr. Volta. By Mr. 
Humphry Davy, Lecturer on Chemistry in the Royal In- 
stitution. Communicated by Benjamin Count of Rumford, 
V.P.R.S. 
Read June 18, 1801. 
I. All the Galvanic combinations analogous to the new 
apparatus of Mr. Volta, which have been heretofore described 
by experimentalists, consist (as far as my knowledge extends) 
of series containing at least two metallic substances, or one 
metal and charcoal, and a stratum of fluid. And it has been 
generally supposed, that their agencies are, in some measure, 
connected with the different powers of the metals to conduct 
electricity. But I have found that an accumulation of Galvanic 
influence, exactly similar to the accumulation in the common 
pile, may be produced by the arrangement of single metallic 
plates, or arcs, with different strata of fluids. 
The train of reasoning which led to the discovery of this fact, 
was produced by the observation of some phenomena relating 
to the connection of chemical changes with the evolution of 
Galvanic power. 
It appeared, in several experiments, that series of double me- 
tallic plates, incapable of acting as Galvanic combinations, when 
arranged in the proper order, with portions of water, were rea- 
dily made to produce Galvanic effects, by being alternated with 
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