44 ON SOME CHEMICAL AGENCIES OF ELECTRICITY. 



doubt, that the principle of action is the same in common 

 and the Voltaic electricity*. 



VII. On the general Principles of the chemical Changes pro- 

 duced by Electricity. 



General prin- The experiments of Mr. Bennet had shown, that many 



ciplcsof the bodies brought into contact and afterwards separated, exhi- 



than«res pro- kited opposite states of electricity; but it is to the invest! ga- 



duced by elec tions of Volta that a clear deyelopement of the fact is 



owing; he has distinctly shown it iu the ease of copper and 



zinc, and other metallic combinations; and has supposed that 



it also takes place with regard to metals and fluids. 



In a series of experiments made in 180lt» on the con* 

 struction of electrical combinations by means of alternations 

 of single metallic plates, and different strata of fluids, I ob* 

 eerved, that, when acid and alkaline solution* were employed 

 as elements of these instruments, the alkaline solutions al- 

 ways received the electricity from the metal, and the acid 

 always transmitted it to the metal ; thus, in an arrangement 

 of which the elements were tin, water, and solution of potash, 

 the circulation of the electricity was from the water to the 



* This had been shown, with regard to the decomposition of water, by 

 £)r. Wollaston's important researches.— By carefully avoiding sparks,. 1 

 "have been able to obtain the two constituents in a separate stale. In an 

 experiment in which a fine platina point cemented in glass, and con- 

 nected by a single wire with the positive conductor of this machine, was 

 plunged in distilled water in an insulated state, and the electricity dissi- 

 pated into the atmosphere by means of moistened filaments of cotton, 

 oxigen gas, mixed with a little nitrogen gas, was produced; and when 

 the same apparatus was applied to the negative conductor hidrogen gas 

 was evolved, and a minute portion of oxigen and nitrogen gasses : but 

 neither of the foreign products, the nitrogen gas in the one case and the 

 nitrogen and oxigen gasses in the other, formed as mush as -jV pait of 

 the volume of the g^es } and there is every reason to suppose, that they 

 were derived from the extrication of common air, which had been dis- 

 ud in the water. This result, which, when I first obtained it in 1803, 

 aied very obscure, is now easily explained; the alternate products 

 must have been evolved at the points of the dissipation of the elec- 

 tricity. 



f See Phil. Trans. Vol. XCI, j age 397. 



tin, 



