ON THE MIGRATION OF IONS DURING ELECTEOLYSIS
BY
W. HITTORF
The explanation which we now give of the process of electrolysis was first proposed, in its general outlines, by Grotthuss in 1805. According to it, the two ions which are simultaneously set free do not come from the same molecule[1] of the electrolyte, but belong to different ones—namely, those which are in immediate contact with the electrodes. The other components of the compound from which they separate unite at once with the opposite components of the next adjacent molecules; this process takes place between the opposite components of all adjacent molecules in the interior of the electrolyte, and holds them together.
"I conclude from this," remarks Grotthuss,[2] "that were it possible to produce in water a galvanic current flowing in a circle, without the introduction of metallic conductors, all water particles lying in this circle would be decomposed and immediately after recombined; whence it follows that this water, although it actually undergoes galvanic decomposition in all of its particles, would nevertheless always remain water."
This conception of electrolysis was so natural that it could not fail to supersede the other more or less far-fetched hypotheses which assumed both liberated ions to arise from the same molecule of the electrolyte. It explained without further assumption, the numerous experiments which H. Davy[3] published soon afterwards on the transference of components to the electrodes.
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