78 oN THE THEORY OF GALVANISM. 



through the water, and tranfmits it to the negative end of the 

 pile. If the wire terminate in pure water, the hidrogen is dif- 

 engaged in the form of gas ; but if a metallic fait be diflblved 

 in the water, the hidrogen is attracted by the oxide, and this 

 lafl reduced to the date of a metal. The phenomena exhibit- 

 ed in this procefs are often peculiarly beautiful, and the ex- 

 treme delicacy which the apparatus pofleffes in difcovering 

 even the minuted metallic impregnations, fuggefts its probable 

 utility in the analytical operations of chemidry. 

 How far galvan- 5. A very intereding fubject of inquiry here prefents itfelf, 



o^ dearth?- V1Z ' in what de S ree wil1 our theoretical notions of the action 

 ©ries. and properties of the electric fluid be influenced by the galva- 



nic difcoveries ? The theory of Dr. Franklin, as well as the 

 elegant one propofed by M. AEpinus, feems to be adapted 

 only to thofe cafes in which the electric fluid previoufly exid- 

 ing in bodies, was altered either with refpecl to its difpofition 

 or quantity. But we are now in pofleflion of an apparatus by 

 which it is actually generated, a circumftance with which we 

 were until lately unacquainted, and confequently our hypothe- 

 cs, being a general deduction from facts, will at lead require to 

 he extended, perhaps in fome indances new -modelled. 

 Chemical theory The pile of Volta affords many illudrations of the modern 

 refitedTv C thefe~ cnem * ca * doctrines, which appear the more driking as effected 

 difcoveries. by experiments made with a different object in view, and pro- 

 duced by an agent which cannot be fuppofed capable of affect- 

 ing the refults. The grand quedion refpecting the decompofi- 

 tion of water, if it dood in need of farther fupport, derives 

 powerful confirmation from the experiments fird performed by 

 Mr. Nicholfon and Mr. Carlifle, and dnce repeated with va- 

 rious modifications. The experiments made with the galvanic 

 apparatus alfo confirm our ideas refpecting the compofition of 

 ammoniac and nitric acid, and confiderably add to our know- 

 ledge of the action which takes place between acids and metals. 

 They beautifully exhibit the powerful effects produced by oxi- 

 gen and hidrogen when in a condenfed or uncombined date, 

 and promife to afford the chemid a valuable opportunity of 

 employing in his different operations thefe bodies in a date of 

 abfolute purity. Every one intereded in the progrefs of philo- 

 fophical knowledge, will regard with admiration the difcovery 

 of an apparatus, which has enabled him to develope fome of 

 4 the 



