Marvels of Scientific Invention - The Original Classic Edition. Corbin Thomas

of it remains adhering to the plate. The oxygen combines with the lead of its plate and so is safely stored up there in the form of oxide of lead. This storage of hydrogen upon the one plate and oxygen on the other cannot go on indefinitely, and so as soon as the limit is reached the cell is fully charged. Passage of further current is then simply waste.

       The dynamo or primary batteries which are used for charging having been disconnected, the two plates can be connected together through lamps, motors, or in any other desired way, and the current will then flow out again, the opposite way to that in which it entered, just as a stone thrown up in the air returns the opposite way. The current which comes out is, in fact, a sort of reflex action arising from that which went in, the mechanism by which it is produced being the reabsorption of the oxygen and hydrogen into the electrolyte.