Mditional Remarks on Galvanic EUHrieity, aifj 



and filver, each l,6 inches fquare, well cemented together, were Introduced into each of 

 thefe grooves or notches, and afterwards cemented into the trough by a compofiiion of 

 rofin and wax, fo perfectly, that no water could pafs from one cell to the other, nor be- 

 tween the plates of zine and filver. This circumftance muft be ftridlly attended to, elfe 

 the machine will be extremely imperfeft. When all the plates were thus fecured in the 

 trough, the interftices or cells formed by the different pairs of plates were filled with a 

 folution of the muriate of ammonia, which here fupplied the place of the moiltened papers 

 in the pile, but anfwered the purpbfe much better. It ishaTdly neceffary to obferve, that 

 in fixing the zinc and filver plates, they muft be placed regularly, as in the pile, viz. alter- 

 nately zinc and filver, the filver plate being always on the fame fide. When a communication 

 was made between the firft and laft cell, a ftrong fliock was felt in the arms, but fomewhat 

 different from that given by the pile, being quicker, lefs tremulous, and bearing a greater 

 refemblance to the common eleftrical fliock. I conftru6ted two of thefe machines, which 

 contained in all too pairs of plates; thefe when joined together, gave a very ftrong ihock, 

 and the fpark could be taken in the day time at pleafure ; but what furprized me not a little, 

 was the very flender power which they pofTefTed in decompofing water; in this refpedb 

 they were certainly inferior to a pile of 30 pairs, although fuch a pile would not give a 

 fhock of one third the ftrength. 



This apparatus retained its power for many days, and would in all probability have re- 

 tained it much longer, had not the fluid got between the dry furfaces of the metals. To 

 remedy this defeft, I have now foldered the zinc and filver plates together, and find that 

 this method anfwers yery well. 



The zinc plates may be cleaned at any time, by filling the different cells for a few mi- 

 nutes with the dilute muriatic acid. Ahhough this apparatus may not intirely fuperfede 

 the pile, efpecially if it fliould be found to decompofe water, &c. but flowly, yet in other 

 refpefts it will no doubt be found very convenient and portable. 



Having been lately favoured by Mr. Howard with narrow flips of platina, of a confidc- 

 rable length, I repeated the experiments refpe£ling the decompofition of • wate^, and with 

 very nearly the fame refults. Seven meafures of the compound gas obtained in the man- 

 ner formerly defcribed, being exploded over mercury by the eleftric fpark, there remained 

 no more than i of a meafure, or -^^ of the whole ; this appeared to be azote, for it fuf- 

 fered no diminution with nitrous gas, nor was it inflammable, I likewife mixed one mea- 

 fure of this compound gas with two of nitrous gas, and the diminution amounted to one 

 meafure; nearly one third of the whole was therefore oxygenous gas, the remaining two 

 thirds being hydrogen gas, with a little az.r^te. 



Having found that the folutions of metals in acids were decompofed by this influence, 

 I next wifhcd to afcertain if their folutions in alkalies, more particularly ammonia, could 

 be decompofed in the fame way. For this purpofe, I added to a dilute folution of 

 the nitrate of filver fomc pure ammonia, until the mixture fmelled ftrongly of 

 the latt :r fubflance. This mixture was introduced into a glafs tube fecured by corks 

 in the "ufual way, and filver wires applied. When the tube was placed in the circle 



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