S6 Dr. IIarc*s Defagrator and Calonmoior^ 



one so well calculated to conduct away electricity, the oth- 

 er so favourable to the radiation of caloric." 



Pursuliig the same subject in a subsequent memoir, also 

 published in your Journal I thus expressed myself, ''As 

 yet no ade(jqate reasons have been given why, in opera- 

 ting with the pile, it is not necessary, as in the process of 

 Van Marum and Wollaston, to enclose the wires in glass 

 or sealing wax, in order to make' the electricity emanate 

 from a point within a conducting fluid. The absence of 

 this necessity is accounted for, according to my hypothesis 

 by the indisposition which the electric fluid has to quit the 

 caloric in union with it, and the almost absolute incapacity 

 which caloric has to pass through fluids unless by circula- 

 tion. 1 conceive that in galvanic combinations, electro- 

 caloric may circulate through the fluids from the positive 

 to the negative surface, and through the metal from the 

 negative to the positive. In the one case caloric subdues 

 the disposition which electricity has to diffuse itself through 

 fluids, and carries it into circulation. In the other, as met- 

 als are excellent conductors of caloric, the prodigious pow- 

 er which electricity has to pervade them agreeably to any 

 attractions which it may exercise operates almost without 

 restraint- This is fully exemplified in my galvanic defla- 

 ^rator, where eighty pairs are suspended in two recipients, 

 brty successively in each, and yet decompose potash with 

 .the utmost rapidity, and produce an almost intolerable sen- 

 sation when excited only by fresh river water. I have al- 

 ready observed that the reason why galvanic apparatus 

 composed of pairs consisting each of one copper and one 

 zinc plate, have not acted well without insulation ; was be- 

 cause electro-caloric could retrocede in the negative, as 

 well as advance in the positive direction." 



Agreeably to these views, in order to prevent the escape 

 of the electricity put into motion by the series, the caloric 

 must bear a certain proportion to it. It is to be inferred, 

 consistently with the same hypothesis, that this proportion 

 did not exist in the series which you connected with the 

 deflagrator. The fluid presented to the latter had too 

 much electricity in it; and hence instead of passing into 

 circulation, escaped. When the coils were suspended in 

 air, this escape was less favored than when they were cov 

 eted by the diluted acid* Faithfully Yours. 



ROBERT HARE. 



f» 



