LTe Dr. Hare on a neiv Theory of Galvanism, [Sept. 



Pure C'oetricity does not expand the slips of gold leaf, between 

 which it causes repulsion, nor does caloric cause any repulsion in 

 the ignited masses which it expands. But as the compound 

 fluid extricated by galvanic action, which I shall call electro- 

 caloric, distributes itself through the interior of bodies, and is 

 evidently productive of corpuscular repulsion, it is in this respect 

 more allied to caloric than to electricity. 



It is true that when common electricity causes the deflagra- 

 tion of metals, as by the discharge of a Leyden jar, it must be 

 supposed to insinuate itself within them, and cause a reaction 

 between their particles. But in this case, agreeably to my 

 hypothesis, ihe electric fluid combines with the latent caloric 

 previously existing there, and, adding to its repulsive agency, 

 causes i< to overpower cohesion. 



Sir Humphry Davy was so much at a loss to account for the 

 continued ignition of wire at the poles of a voltaic apparatus, 

 that he considers it an objection to the materiality of heat ; 

 since the wire could not be'imagined to contain sufficient caloric 

 to keep up the emission of this principle for an unlimited time. 

 But if we conceive an accumulation of heat to accompany that 

 of electricity throughout the suites, and to be propagated from 

 one end to the other, the explanation of the phenomenon in 

 question is attended by no difficulty. 



The effect of the galvanic fluid on charcoal is very consistent 

 with my views, since, next to metals, it is une of the best 

 conductors of electricity, and the worst of heat, and would, 

 therefore, arrest the last, and allow the other to pass on. Though 

 peculiarly liable to intense ignition, when exposed between the 

 poles of the voltaic apparatus, it seems to me it does not display 

 this characteristic with common electricity. According to Sir 

 Humphry Davy, when in connexion with the positive pole, and 

 communicating by a platina wire with the negative pole, the 

 latter is less heated than when, with respect to the poles, the 

 situation of the wire and charcoal is reversed. The rationale is 

 obvious : charcoal, being a bad conductor, and a good radiator, 

 prevents the greater part of the heat from reaching the platina, 

 when placed between it and the source'whence the heat flows. 



I had observed that as the number of pairs in Volta's pile had 

 been extended, and their size and the energy of interposed 

 agents lessened, the ratio of the electrical effects to those of heat 

 had increased ; till in De Luc's column they had become com- 

 pletely predominant ; and, on the other hand, when the pairs 

 were made larger and fewer (as in Children's apparatus), the 

 calorific influence 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 

 elementary battery of Wollaston, though productive of an eva- 



