1840.] The Galvanic Battery. 1177 



more effectual than any connection formed between that metal and it 

 by means of any decomposable bodies or electrolytes, because when 

 they are used, the chemical affinities between them and the zinc pro- 

 duce a contrary and opposing effect to that which is influential in the 

 dilute acid ; or if that opposing action be but small, still the affinity 

 of their component parts for each other has to be overcome, for they 

 cannot conduct without suffering decomposition, and this decomposition 

 is found experimentally to re- act upon the forces which in the acid 

 tend to produce the current, and in some cases entirely to neutralise 

 them. Where direct contact of the copper and zinc takes place, these 

 obstructing forces are not brought into action, and therefore the pro- 

 duction and circulation of the electric current are highly favoured. 

 Hence the cause of the very great importance-of metallic contact in the 

 Voltaic Battery. 



The liquid in the cells of the Battery has the power of retarding 

 the circulation of the electricity generated, and it acts injuriously in 

 greater or less proportion, according to the quantity of it between the 

 zinc and copper plates, or, in other words, according to the distances 

 between their surfaces. Hence then the reason of the great increase 

 of power obtained by approximating the two metals, and Faraday states 

 that not only is this power greater on the instant, but also that the 

 sum of the transferable power in relation to the whole sum of the che- 

 mical action at the plates is much increased. Double coppers owe 

 their advantages in part to the same cause, but derive their superiority 

 chiefly from the circumstance that they virtually double the acting 

 surface of the zinc, or nearly so, the action on both sides of the metal 

 being converted into transferable force, and the power of the Battery, 

 as to the quantity of electricity evolved, highly exalted in consequence. 



The cause of the heat excited during the passage of a Voltaic current, 

 remains still enveloped in considerable obscurity, and a more intimate 

 acquaintance with the modes of action of electrical forces will be 

 required, ere the difficulty can be fully removed. Uncertain as we 

 still are of the precise nature of the electric current, the conclusion 

 that the ultimate atoms of matter are in some way endowed or asso- 

 ciated with electrical powers, is forced upon us by nearly all the great 

 facts of the science. The researches of Faraday have led him to notice 

 the truly enormous quantity of this electrical power, associated with 



