Text: The hypothesis of Professor Weber makes the equilibrium of electricity unstable in any conductor of moderate dimensions and renders possible the development of infinite quantities of work from finite bodies. I do not find that the objections brought forward at first by Sir W. Thomson and Professor Tait in their Treatise on Natural Philosophy and discussed and specialized afterward by myself have been invalidated by the discussions going on about this question. The hypothesis of Riemann, which he did not himself publish during his lifetime, labors under the same objection and is at the same time in contradiction to Newton's axiom, which established the equality of action and reaction for all natural forces. The hypothesis of Professor Clausius avoids the first objection but not the second, and the author himself has conceded that this objection could be removed only by the assumption of a medium filling all space, between which and the electric fluids the forces acted. The present development of science shows then, I think, a state of things very favorable to the hope that Faraday's fundamental conceptions may in the immediate future receive general assent. His theory, indeed, is the only one existing which is at the same time in perfect harmony with the facts as far as they are observed and does not, beyond the reach of facts, lead into any contradiction to the general axioms of dynamics. Clerk Maxwell himself has developed his theory only for closed conducting circuits. I have endeavored during the last few years to investigate the results of this theory also for conductors not forming closed circuits. I can already say that the theory is in harmony with all the observations we have on the phenomena of open circuits: I mean (1) the oscillatory discharge of a condenser through a coil of wire, (2) my own experiments on electromagnetically induced charges of a rotating condenser, and (3) Mr. Rowland's observation on the electromagnetic effect of a rotatory disc charged with one kind of electricity. The deciding assumption which removes the theoretical difficulties is that introduced by Faraday, who assumed that any electric motion in a conducting body which charges its surface with electricity is continued in the surrounding insulating medium as beginning or ending dielectric polarization with an intensity equivalent to that of the current. A second inference from this supposition is that forces working at a distance do not exist -- or are, at least, unimportant -- when compared with the tensions and pressures of the dielectric medium. It is not at all necessary to accept any definite opinion about the ultimate nature of the agent which we call electricity. Faraday himself avoided as much as possible giving any affirmative assertion regarding this problem, although he did not conceal his disinclination to believe in the existence of two opposite electric fluids. For our own discussion of the electrochemical phenomena, to which we shall now turn, I beg permission to use the language of the old dualistic theory, which considers positive and negative electricity as two imponderable substances, because we shall have to speak principally of relations of quantity. We shall try to imitate Faraday as well as we can by keeping carefully within the domain of phenomena and, therefore, need not speculate about the real nature of that which we call a quantity of positive or negative electricity. Calling them substances of opposite sign, we imply with this name nothing else that the fact that a positive quantity never appears or vanishes without an equal negative quantity appearing or vanishing at the same time in the immediate neighborhood. In this respect they behave really as if they were two substances which cannot be either generated or destroyed but which can be neutralized and become imperceptible by their union. I see very well that this assumption of two imponderable fluids of opposite qualities is a rather complicated and artificial machinery and that the mathematical language of Clerk Maxwell's theory expresses the laws of the phenomena very simply and very truly with a much smaller number of hypothetical implications. But I confess I should really be at a loss to explain, without the use of mathematical formulas, what he considers a quantity of electricity and why such a quantity is constant, like that of a substance. The original, old notion of substance is not at all identical with that of matter. It signifies, indeed, that which behind the changing phenomena lasts as invariable, which can be neither generated nor destroyed, and in this oldest sense of the word we may really call the two electricities substances. I prefer the dualistic theory because it expresses clearly the perfect symmetry between the positive and negative side of electric phenomena, and I keep the well-known supposition that as much negative electricity enters where positive goes away, because we are not acquainted with any phenomena which could be interpreted as corresponding with an increase or a diminution of the total electricity contained in any body. The unitary theory, which assumes the existence of only one imponderable electric substance and ascribes the effects of opposite kind to ponderable matter itself, affords a far less convenient basis for an electrochemical theory. I now turn to the second fundamental problem aimed at by Faraday, the connection between electric and chemical force. Already, before Faraday went to work, an elaborate electrochemical theory had been established by the renowned Swedish chemist, Berzelius, which formed the connecting link of the great work of his life, the systematization of the chemical knowledge of his time. His starting point was the series in which Volta had arranged the metals according to the electric tension which they exhibit after contact with each other. Metals easily oxidized occupied the positive end of this series, those with small affinity for oxygen the negative end. Metals widely distant in the series develop stronger electric charges that those near each other. A strong positive charge of one metal and a strong negative of the other must cause them to attract each other and to cling to each other. The same faculty of exciting each other electrically was ascribed by Berzelius to all the other elements; he arranged them all into a series, at the negative end, oxygen, chlorine, bromine, etc. Two atoms of different elements coming into contact are supposed to excite each other electrically, like the metals in Volta's experiment. Berzelius' conceptions about the distribution of opposite electricities in the molecules, and his deductions regarding the intensity of these forces, were not very clear and not in harmony with the laws of electric forces which had already been developed by Green and Gauss. A fundamental point, which Faraday's experiment contradicted, was the supposition that the quantity of electricity collected in each atom was dependent on their mutual electrochemical differences, which Berzelius considered the cause of their apparently greater chemical affinity. His theory of the binary character of all chemical compounds was also connected with this electrochemical theory. Two elements, he supposed-one positive, the other negative-could unite into a compound of the first degree, a basic oxide or an acid; two such compounds, into a compound of the second degree, a salt. But there was nothing to prevent one atom of every positive element from uniting as directly with two, three, or even seven of another negative element as with one. The same was assumed by Berzelius for negative elements. The modern experience of chemistry directly contradicts these statements. But although the fundamental conceptions of Berzelius' theory have been forsaken, chemists have not ceased to speak of positive and negative constituents of a compound body. Nobody can overlook that such a contrast of qualities as was expressed in Berzelius' theory really exists, well developed at the extremities, less evident in the middle terms of the series, and playing an important part in all chemical actions, although often subordinated to other influences. When Faraday began to study the phenomena of decomposition by the galvanic current, which of course were considered by Berzelius as among the firmest supports of his theory, he put a very simple question- the first question, indeed, which every chemist speculating about electrolysis ought to have thought of. He asked, what is the quantity of electrolytic decomposition if the same quantity of electricity is sent through several electrolytic cells? By this investigation he discovered that most important law, generally known under his name but called by him the law of definite electrolytic action.

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