A new Theory of Galvanism. 209 



predominant; and, on the other hand, when the pahs were made 

 larger and fewer, (as in Children's apparatus,) the calorific in- 

 Huence had gained the ascendancy. I was led to go further in 

 this way, and to examine whether one pair of plates of enormous 

 size, or what might be equivalent thereto, would not exhibit 

 heat more purely, and demonstrate it equally with the electric 

 fluid, a primary product of Galvanic combinations. The ele- 

 mentary battery of Wollaston, though productive of an evanes- 

 cent ignition, was too minute to allow him to make the observa- 

 tions which 1 had in view. 



Twenty copper and twenty zinc plates, about nineteen inches 

 square, were supported vertically in a frame, the different metals 

 alternating ac one half-inch distance from each other. All the 

 plates of the same kind of metal were soldered to a common slip, 

 so that each set of homogeneous plates formed one continuous 

 metallic superficies. When the copper and zinc surfaces thus 

 formed are united by an intervening wire, and the whole im- 

 merged in an acid or aceto-saline solution, in a vessel devoid of 

 partitions, tlie wire becomes intensely ignited ; and when hy- 

 drogen is liberated it usually takes fire, producing a very beau- 

 tiful undulating or coruscating flame. 



I am confident, that if Volta and the other investigators of 

 Galvanism, instead of multiplying the pairs of Galvanic plates, 

 had sought to increase the effect by enlarging one pair as I have 

 done, (for I consider the copper and zinc surfaces as reduced to 

 two by the connexion,) the apparatus would have been considered 

 as presenting a new mode of evolving heat as a primary effect 

 independently of electrical influence. There is no other indica- 

 tion of electricity when wires from the two surfaces touch the 

 tongue, than a slight taste, such as is excited by small pieces of 

 zinc and silver laid on it and under it, and brought into contact 

 with each other. 



It was with a view of examining the effects of the proximity 

 and alternation in the heterogeneous plates, that I had them cut 

 into separate squares. By having them thus divided, I have 

 been enabled to ascertain, that when all of one kind of metal are 

 ranged on one side of the frame, and all of the other kind on the 

 other side of it, the effect is no greater than might be expected 

 from one pair of plates. 



Volta, considering the changes consequent to his contrivance 

 as the effect of a movement in the electric fluid, called the pro- 

 cess electro-motion, and the j)latcs producing it electro-motors. 

 But the phcTenomena show tliat the plates, as I have arranged 

 them, are calori-motors, or heat-movers, and the effect c:alori- 

 motion. That this is a new view of the subject, may ibenferred 

 from the following passage in Davy's Elements. That great 



Vol. 54. No. 257. Set)t. 1819. ' O chemist 



