with our experience and observation, as no body pushes or pulls another body, be it what it may, unless both bodies are joined together by some medium which transmits the push or the pull. Professor Lodge, in his _Modern Views of Electricity_, has illustrated from an electrical standpoint how the pressure and tension in any electrical field may be transmitted from particle to particle, or atom to atom. He supposes that a positive atom of electricity rotates in one direction while a negative atom rotates in the opposite direction. In any electric field these atoms are so associated with each other, that when one atom revolves, it makes the other to revolve in the opposite direction, with the result, that the spin or rotation is transmitted through the medium at a speed dependent upon the density of the medium. For fuller details of the description I must refer the reader to the work already referred to. What I wish to call the reader's attention to is, that the tension and pressure in this field is not transmitted across a vacuum, in some unknown way, but is transmitted solely by a physical medium. The action is direct, and is produced, and alone produced, continued, and perpetuated by a physical medium which is composed of atoms of negative and positive electricity. So that if one body _A_ acts upon another body _B_, it acts upon _B_ solely and entirely by the action of the atoms which form the magnetic lines of force, and the equipotential surfaces around the electrified body, and that action can be traced mentally step by step across the intervening space that may exist between the two bodies. It is in an exactly similar manner, that the Attraction of Gravitation, which we conceive to be the same as electrical attraction, is transmitted from body to body in the atomic, molecular, planetary or stellar world. In each and every case, the pressure and tensions, which are inseparably connected, are transmitted by the atoms of the electro-magnetic Aether, that is, by the positive and negative atoms of electricity of which, according to Professor Lodge and Dr. Larmor, the Aether is composed. So that, if the sun acts on the earth, by the centrifugal force, it acts on it solely through and by the pressures which are originated in the atomic Aether by the central body. If the sun attracts the earth, by the centripetal force, that action can also be traced to the tensions that are originated among the atoms of the electro-magnetic Aether. There is nothing mysterious about the phenomenon in either case, as by accepting this view of an atomic Aether with its dual character of positive and negative electricity, the action may be traced mentally from point to point across the so-called intervening space that exists between any two bodies. In each and every case, wherever the centripetal or centrifugal force acts, the action is direct, because it is caused by a physical medium, which physical medium is in direct contact with each body acted