Electrochemistry

Abstract

Faraday¹ said: ‘the anions must move in accordance with each other in one direction, and the cations in the other. Nay, more than that, equivalent portions of these bodies must advance in opposite directions’, i.e. the ions move in opposite directions with equal speeds. L. Gmelin² noticed that in the electrolysis of copper sulphate solution the liquid near the cathode was decolorised. C. S. M. Pouillet³ found that in electrolysing a solution of gold chloride only the liquid near the cathode lost in gold content; he assumed that the action was exerted only by the cathode, the anode being indifferent: ‘le pôle positif reste sans action décomposante’, the chlorine liberated passing ‘par une série de décompositions et de récompositions successives’ to this pole. With other chlorides there was some action but Pouillet explained his results by l’inégale puissances des poles’.