208 A new Theory of Galvanism, 



cation of their properties, consequent to some such union, they 

 could not, in piles of thousands of pairs, be carried forward 

 through the open air and moisture ; the one so well calculated 

 to conduct away electricity, the other so favoural)le to the radi- 

 ation of caloric. 



Pure electricity does not expand the slips of gold leaf, between 

 which it causes re])ulsion, 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 re-action 

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

 thesis, tlie electric fluid combines with the latent caloric previous- 

 ly existing there, and, adding to its repulsive agency, causes it 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 suflicient 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 series, and to be propagated from one 

 end to the other, the explanation of the phaenomeiion in ques- 

 tion 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 one of the best con- 

 ductors 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 cha- 

 racteristic with common electricity. According to Sir Humphry" 

 Davy, when in connexion with the positive pole, and communi- 

 cating 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 : char- 

 coal 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 tiieir 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 completely 



predominant ; 



