Hart's Calorimotor, 415 



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, the electric fluid combines with the latent caloric 

 previously 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 Voltatc 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 un- 

 limited 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 

 phenomenon in question is attended by no difficulty. 



The eflfect of the Galvanic fluid on charcoal is very consist- 

 ent with my views, since, next to metals, it is one 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 re- 

 spect 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 the iner- 



* Possibly the electric fluid causes decompositions when emitted from an im- 

 palpable point (as in ihe experiments of Wollaston) because its repulsive agency 

 is concentred between integral atoms, in a mode analogous to that here referred 

 to; a filament of water in the one case, and of wire in the other, being the me- 

 dium of discharge. 



32* 



