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First case:—
A Circuit of Uniform Material and Uniform Size of Conductor.—By means of the first and third fundamental positions, we obtain a distinct insight into the primary galvanic phenomenon, as follows. Imagine, for instance, a ring everywhere of equal thickness and homogeneous, having at any one place one and the same electrical potential; i.e., inequality in the electrical state of two surfaces situated close to each other; from which causes, when they have come into action, and the equilibrium is consequently disturbed, the electricity will in its endeavor to re-establish itself, if its mobility be solely confined to the extent of the ring, flow off on both sides.
If this tension were merely momentary, the equilibrium would very soon be re-established; but if the tension is permanent, the equilibrium can never be restored; but the electricity by virtue of its expansive force, which is not sensibly restrained, produces in an almost inappreciably brief space of time, a state which
