114 On some Chemical Agejicies of Electricity. 



VII. Oti the general Principles of the chemical Chart geS 

 produced lij Electricity. 



The experiments of Mr. Bennet bad shown that many 

 bodies brought into contact and afterwards separated, exhi- 

 bited opposite states of electricity ; but it is to the investi- 

 gations of Volta that a clear development of the fact is ow- 

 ing; he has distinctly shown it in the case of copper and 

 zinc, and other metallic combinations ; and has supposed 

 that it also takes place with regard to metals and fluids. 



In a scries of experiments made in 1801 * on the con- 

 struction of electrical combinations by means of alternations 

 of single metallic plates, and dillerent strata of fluids, I ob- 

 served that whtu acid aiid alkaline solutions were employed 

 as elements of these instruments, the alkaline solutions al- 

 ways received the electricity from the metal, aiid the acid 

 alwav? transmitted it to the metal : thus, in an arrangement 

 0? wliich the elements were tin, water, and solution of pot- 

 a.-h, the circulation of the electricity was from the water to 

 the tin, and from the tin to the solution of potash ; but 

 in an arrangement composed of weak nitric acid, water^ and 

 tin, the order was from the acid to the tlnj and from the 

 tin to the water. 



These principles seem to bear an immediate rclatioii to 

 Ihc general jihcenomena of decomposition and transference, 

 which have been the subject of the preceding details. 



In the simplest case of electrical acti6n, the alkali which 

 receives electricity from the metal would necessarily, on 

 beino- S&parittcd from it, appear positive, whilst the acid 

 under similaf Circumstances would be negative ; and these 

 bodies having respectively, v»'ith regard to the metals, that 

 whicli mav be called a positive and a negative electrical 



hitro"'en gases: but neither of the foreign products, the nitrogen g£s in the 

 one cast, And tlie nitrogen and Oxygen gases in tlie other, formed as much aj 

 l-30th part of tlic volume of the gases; and there is every reason to suppose 

 that they were derived from the extrication of common air, which had been 

 diasolvcd in t!ie water. This result, which when I first obtained it in 1803 

 appeared very obscure, is now easily explained; the alternate products must 

 have been evolvid at the points of the dissipation of the electricity; 

 • See Phil. Trans, vu!. rci. p. 397, 



energy, 



