Collateral science is further aiding us to perceive that there is a different molecular arrangement in diaphanous or isolating bodies, as compared with opaque or conducting bodies, such as metals, etc. How far the new discoveries of Graham, which have demonstrated the presence of gases in metals and other substances held there by what he terms "occlusion," may throw light on this interesting and intricate subject, is as yet problematical; but I must add that the power, by means of heat, of making metals give up large volumes of these occluded gases, proves the existence of spaces between the molecules capable of
and not to be the result of a second current in the opposite direction. Further, as a new demonstration, we may accept the statement that electricity is now understood to be an etherial fluid, and not, like light and sound, to be a result of the mere vibration of a luminous ether, and that this fluid is propagated by layers. The evidence of electricity being a fluid, rests chiefly on the greatly increased intensity and condensation of power, developing more light and heat, when conducting wires are diminished in sectional area; as evidenced also in Geisler's tubes—the intensification following the natural law of fluids long since established.
