386 THEORY OF GALVANIC, 



so arranged as to constitute only a single pair 

 of zinc and copper plates of enormous dimen- 

 sions, as in Dr. Hare's calorimotors, the calorific 

 effects are still more remarkable. 



On the other hand, when the battery is com- 

 posed of a large number of metallic plates of 

 small size, and immersed in the same solutions, 

 electricity is evolved, which affects the electrome- 

 ter, communicates a shock, and passes through 

 conductors with a speed approaching that of 

 lightning. * 



These striking facts led Dr. Hare to suppose 

 that both caloric and electricity are developed 

 during all galvanic operations; and that they 



* When the battery is composed of a few large plates, and 

 immersed in an acid solution, caloric is evolved until the acid is 

 decomposed, or until the metallic plates are consumed. But if 

 the battery be composed of a large number of small plates of the 

 same metals, and immersed in the same acid, electricity is pro- 

 duced, until the plates or acid are consumed by oxidation ; 

 which demonstrates the identity of caloric and electricity beyond 

 the possibility of a doubt ; for it would be a perversion of com- 

 mon sense to suppose, that by merely changing the size and 

 number of the plates, a radically different fluid could be evolved, 

 while the metals, and solutions in which they are immersed, are 

 the same. Shall I be asked for clearer proofs that the latent 

 caloric of acids is the basis of electricity ? We might as well be 

 asked to prove that the sun is the fountain of light and heat ; or 

 that rain accompanies lightning, 



It is generally known that the most powerful batteries are 

 composed of bodies which act with the greatest energy upon 

 each other, such as zinc, copper, and nitric acid; and that such 

 as undergo no chemical changes exhibit no electrical effects, 

 such as gold, silver, and water. 



