Atoms and Electrons.
"To explain the operation of this device, we must remind the reader that modern research has shown that the atoms of which material substances are composed are themselves formed of still smaller atoms of electricity called electrons. An atom of matter is a very small thing. If 250,000,000 atoms of copper or gold were put in a row, like marbles, touching each other, the row would only be an inch long. But an electron is still smaller. Its diameter is probably only one hundred thousandth of that of an atom. Electrons are of two kinds, called positive and negative, and an atom is a sort of solar system in which a number of negative electrons revolve round a nucleus composed chiefly of positive electrons. In the case of metals, some of these negative electrons escape easily from the atoms and probably jump about from atom to atom like bees in a garden flitting from flower to flower. The speed with which these free electrons dart about is sixty miles per second.
Procession of Electrons.
"The state we call an electric current in a wire is merely these free electrons as a whole drifting in one direction or surging to and fro with but ceasing their irregular motion." 