formed hy Jingle Mdalllc Pl&fcs and Fluids. 203 



It appeared, in feveral experiments, that feries of double 

 metallic plates, incapable of a6ling as galvanic combinations, 

 when arranged in the proper order, with portions of water, 

 were readily made to produce galvanic effects, by being al- 

 ternated with acids, or other fluids capable of oxidating one 

 onlv of the metals of the feries. Thus, double plates, com- 

 pofed of filver and gold, (metals which have been fuppofed 

 to differ very little in their powers of conducing eleftricity,) 

 produced galvanic aclion, when placed in contaft, in the 

 common order, with cloths moiftened in diluted nitric acid. 

 And copper and filver aiikd powerfully with nitrate of mer- 

 cury. 



Thefe fafts induced me to fuppofe, that the alternation of 

 two metallic bodies with fluids, was cfllential to the produc- 

 tion of accumulated galvanic influence, only fo far as it fur- 

 niflied two conducing furfaces of different degrees of oxida- 

 bility ; and that this produtlion would take place, if fingle 

 ■metallic plates could be connefted together by different fluids 

 in fuch a manner, that one of their iurfaces only fliould un- 

 dergo oxidation, the arrangement being regular. 



On this fuppofltion, I made a number of experiments oa 

 diflisrcnt arrangements of Angle metals and fluids; and, after 

 many various ])rocefl!es, I was enabled to afcertain, that many 

 of thefe arrangements could be made aeirive, not onlv when 

 oxidations, but likcwife when other chemical changes werc 

 going on in fome of their parts. 



In defcribing the different galvanic combinations formed 

 by fingle metallic plates and fluids, I flaall divide them into 

 three clafl'es, followino:, in the arrangement, the order of 

 time with regard to dilcovery. 



■ II. The firlt and mofl feeble clafs is compofed, whenever 

 fingle metallic plates, or arcs, are arranged in fuch a maxincr, 

 that two of their furfaces, or ends oppofite to each other, arc 

 in conta6l with different fluids, one capable, and the other 

 incapable, of oxidating the metal. In this cafe, if the feries 

 are numerous, and in reffular alternation, galvanic influence 

 will be accumulated, analogous, in all its effects, to the in-' 

 fluence of the common pile. 



Tin, zinc, and fome other eafilv oxidable metals, aft moft 

 powerfully in this clals of combinations. 



If pieces of poliflicd tin, about an inch fquare and .'>. of 

 an inch thick, be eonnecfed with woollen cloths of the fame 

 lizc, inoilteiied, fome in water, and fome in diluted nitrous 

 acid,) in the following order — tin, acid, water, and fo on, 

 till twenty feries arc put together — a feeble galvanic baticty 

 will jjc formed, capable of acting weakly on the organs of 



Iciilc. 



