Page:The fundamental laws of electrolytic conduction.djvu/62

 The tardy appearance of the ions of an electrolyte which is not in direct contact with the poles, and their failure to appear at all when separated from the electrodes by a liquid with which they form an insoluble compound, were excellent proofs of the theory furnished by Davy.

Notwithstanding the clear conception of electrolysis which Grotthuss had up to this point, as indicated in the remark which I have given above in his own words (we easily realize to-day, as is well known, the premise of the conclusion by an induction current), he fell into serious error in attempting to further fathom the phenomenon. He conceived it to be produced as follows: the metals between which the electrolyte is placed are the seat of two forces, which vary inversely as the square of the distance, and which, acting oppositely on the two components, repel the one and attract the other. All physicists who turned their attention to this subject favored this view more or less for a long time; the name of the poles which was given to the immersed metals corresponded to it. Grotthuss was, however, herein so far in advance of others that he considered (contrary to his hypothesis, to be sure) the forces acting on each particle of the electrolyte everywhere equal in the circle, an assumption which, as is known, is correct for the simplest conditions of the experiment.

Faraday was the first to penetrate deeper into the phenomenon. He conceived the cause of it in exactly the reverse manner, and was thereby led to the great discovery of the fundamental electrolytic action of the current, which now forms the basis of all investigations in electrolysis. By means of this change he brought the theory into harmony with Ohm's law, without knowing the latter.

"I conceive," he says, in § 524 of Experimental Researches, "the effects to arise from forces which are internal, relative to the matter under decomposition, and not external, as they might be considered, if directly dependent on the poles. I suppose that the effects are due to a modification, by the electric current, of the chemical affinity of the particles through or by which that current is passing, giving them the power of acting more forcibly in one direction than in another, and consequently making them travel by a series of successive