tAW OP GALVANISM IN BURNING THE METALS. ^Qjff 



When the French philofophers had afcertained that a feries Introduftion-, 

 of galvanic plates produced etledls on animal fubftances in pro- 

 portion to the number oF plates employed, without any regard 

 to the furface of each plate, they concluded from their ex- 

 periments, that the eifeds of a galvanic battery on metallic 

 liibflances are in proportion to the furfaces of the plates em- 

 ployed. I have lately been engaged in experimeiits with thq 

 moftextenfive galvanic apparatus hitherto conftru6led, from 

 which fome circumftances have occurred, in fome refpeds 

 'militating with the dedudions of the French philofophers. 



A galvanic trough containing one hundred fquare plates ofOnehunditJ 



four inches in the fide, each plate formed of a plate of zinc sa^vauic phte» 



* . , r , . of four incae» 



and copper foldered together; when charged with a folution or fquare burned 

 nitrous acid 'and water in the proportion of about 25 parts half an inch o€ 

 water to one of acid, exhibited a power capable of igniting 

 half an inch of fleel wire of about one feventieth of an inch 

 in diameter. 



When two fuch troughs were combined endwife, the power Other trough* 

 was doubled, and when four were thus arranged, the quantity burned mw? 

 of wire ignited was quadrupled : hence I afcertained in a very v/ire inpropor- 

 extenfive arrangement, that the power is invariably in propor- 5 °"of '?^t""°*" 

 tion to the number of plates employed. 



A galvanic trough confiding of fifty fquare plates of eight A trough of 



inches each in the fide was charged with a fimilar prepared fo- ^^^^l P'^'^'^* ^ 



* r r . much more 



lutlon, and this arrangement I found capable of igniting fix- power, 



teen inches of the fame wire as was employed in the former 



experiment. 



When two, three, and four troughs of the fame fize were —which in- 

 eombined, the lengths of wire ignited proved to be in propor- cjeafed propor- 

 tion to the number of plates employed; fo that two hundred number, 

 eight inch plates ignited more than five feet of wire. 



Thefe experiments prove that the powers increafe in a Examination of 

 greater ratio than as the furfaces of the plates employed. For ^^ J.^^"^'**^ 

 four hundred plates of four inches, containan equal furface with power of largt^ 

 one hundred plates of eight inches; and the former will only P'^*^"' 

 ignite two inches of the fame wire, of which the latter will 

 ignite thirty-two inches. 



If this proportion fliould be obferved in experiments with ^y ^V^^^ ^o^l 

 plates of different fize, it will appear that the powers of ig- bu^rned's ts £* 

 niting, as meafured by the length of wire, increafe, in batteries fquare of tha 

 of the fame total furface, as the fquares of the furfaces of thet'''^^"^^''y ^•'" 

 Elementary plates, lingly taken in each, 



A plate. 



