part of it at the moment, will also move from right to left: and as the oxygen of the water, by its natural affinity for the zinc, moves from left to right, so any other body of the same class with it (i.e. any other anion), under its government for the time, will move from left to right.
Fig. 43.
698. This I may illustrate by reference to fig. 43, the double circle of which may represent a complete voltaic circuit, the direction of its forces being determined by supposing for a moment the zinc b and the platina c as representing plates of those metals acting upon water, d, e, and other substances, but having their energy exalted so as to effect several decompositions by the use of a battery at a (725). This supposition may be allowed, because the action in the battery will only consist of repetitions of what would take place between b and c, if they really constituted but a single pair. The zinc b, and the oxygen d by their mutual affinity, tend to unite; but as the oxygen is already in association with the hydrogen e, and has its inherent chemical or electric powers neutralised for the time by those of the latter, the hydrogen e must leave the oxygen d,
