"288 EXAMINATION OF VOLTa's EXPERIMENTS, &C 



This changed the menftruum, with refpect to its electrical property upon that 

 afertedtobe of t on « Q f thc metal wnereon j t j ]as a ^ed, is exactly the re- 



an oppoute na- ■ J J 



ture to the dec- verfe of that of the parts not acted upon. The part of the 

 trie ftateof the z [ nc thus a & e( j upon, muft confequently be difpofed to throw 

 and therefore 'off its electric fluid, and would give to that part of the copper, 

 produces eleftric which by a like action is difpofed to abforb it) fo that the two 

 furfoees oppefite ^ ates or tne furfaces acted upon would unite and counterba- 

 $o thofe of the lance each other imperceptibly) if it were not oppofed by 

 dr h'Tdonot tne ^ exifting property and mutual action of the two metals 

 pafsfrom zinc to in their parts not a£ted upon by the menftruum ; hence it fol- 

 copper through Iovys that the e i e ft r j c fluid is propelled forwards from the zinc 



the metals and . .. , . ., 



become quief- through the menftruum to the next adjoining copper in the pile 

 cent; but from or trough ; but this can only happen in a progreffive manner, 

 through the fluid, on account of the menftruum being an imperfect conductor, 

 this paffage be- which appears to be an indifpenfible condition to the maintain- 

 '%£& gal- ™S any electric intenfity. 



'wanic current: The fhock or fen fation felt on touching the two oppofite 

 which is progre- enc j s f the galvanic inftrument, depends upon the menftruum, 

 fluid cannot per- together with the refifting property of the two metals in ccn- 

 feclly conduft ta £ # -phe flll ; t i muft be adequately proportioned between be- 

 the eleancity as . n /f r M!l c A 



faft as it is extri- ln g an electric and a perfect conductor. It it were a perfect 

 cated. conductor, the electric fluid would pafs from the zinc through 



The fhock from the menftruum to the next adjoining copper, as quick as it is 

 fuddenw'tra^f- 11 g* ven or ^ ky tne altered part of the zinc ; no accumulation 

 mitted. would enfue, and confequently no fenfation of fhock or dis- 



charge would be perceived. If it were an electric, the electric 

 fluid given off by the altered zinc would be ftopped, and accumu- 

 late till it become pofTelTed of fufficient force to overcome the 

 mutual reiiftance of the two metals in contact, and pafs through 

 by a reverie motion to the copper ; confequently no fenfation 

 would be felt by forming a communication between the two 

 oppofite ends. For though there would be an accumulation, 

 yet it cannot be united ib as to act in concert with that of the 

 other combined metals; being (hut off by the interpofed electric 

 menftruum, and too feeble of itfclf to affect our fenfes. 



ANNOTATION. W. N. 



Short hiftory of At page 396, vol. I. of the quarto feries of this Journal, an 

 inftruments for outline • ; ven of the hiftory of all the inftruments for (hewing 



(hewing minute % p r \ n • • 1/1 



quantities of or meafunng minute quantities or electricity, with a itatement 



electricity. f their advantages and defects. With regard to the condenfer 



difcovered 



