ON GALVANIC PHENOMENA. t^J 



" to be accumulated in the glass, and dissipated in the seal- electricity not 



*' ing-wax. Admitting the existence of an electric fluid, it dete «iimed, 



" would seem to follow, that if it be accumulated in the glass, 



" it must be dissipated in the sealing-ivax: but as far as my 



4 * knowledge goes, it has never been determined, that it is 



" in the glass, and not in the sealing-wax, that the accumu- 



" lation takes place." 



This opinion has led Dr. Maycock to suppose, that it can- and conse- 

 not be determined whether a fluid does enter at a determin- course^rl^th* 

 ed extremity of the pile, and return to the opposite extremity, pile not ascer- 

 when a circuit is established ; but if he had seen my paper ta,ned ' 

 in your Journal for June 1810, he would have known, that I 

 had made this point the object of a long series of experiments, 

 demonstrating that, when the extremities of the pile are con- 

 nected together by a conducting substance, the effects are 

 produced by the circulation of the electric fluid entering the 

 extremity, which, in the pile without a circuit, is positive, 

 and returning to the extremity, which, in the same case, is 

 negative. 



I come to another proposition of Dr. Maycock, p. 27 of Dr. M. sup- 

 the same Number of your Journal, relating to galvanism, pose'adecom- 

 «* The galvanic apparatus,'* he says, " can only be excited ^ cessa y U to 

 " by a decomposable fluid, and this fluid is always decomposed l " e excite- 

 a when the apparatus is excited." Sir H. Davy was at first raent: 

 of the same opinion ; but I have demonstrated by various 

 experiments in your Journal, that no fluid (or liquid) is ne- 

 cessary to produce that excitation with respect to the electri- 

 cal phenomena of the pile; that the only condition of this but tne con_ 

 effect, distinct from the chemical eftects, is, that the groups shown." 

 of two metals in actual contact be separated by u conducting 

 substance not metallic; and as it is a very essential point in 

 galvanism, I shall briefly repeat its proofs. 



This, first, is the cause why, in the second dissection of the Experiment 

 pile above mentioned, where that condition only existed, ihe l )rovin S & ia * 

 electrical phenomena continued ; but not the chemical phe- 

 nomena, which require, as i have proved, a liquid between 

 the metals, in order to produce a corrosion oil their surface. 

 This is demonstrated by Exp. 19 in p. 135 of your Journal 

 for June 181Q. For, when before I had mounted a pile of 76 

 groups composed oi zinc and silver plates 1 6 inch in diame- 

 ter, 



