If, therefore, there is this close identity between electricity and magnetism, then in view of the fact that all electricity is due to the motions of the universal Aether, it must follow that all magnetism is also due to motions of the same aetherial medium, which is as universal as it is invisible. What these motions are has already been indicated by previous statements in this article, being comprised of circular or rotatory motions of the aetherial electric medium about any body, whether that body be an atom, planet, or sun or star. Such a conclusion as this is perfectly in harmony with Maxwell's electro-magnetic theory of light, as the conclusion that he arrived at in that theory was, that the light waves were identical in nature and character with electro-magnetic waves produced by an electro-magnetic source. Up to the present we have only dealt with the electric character of those waves, and have therefore now to deal with the magnetic character of the same. So that throughout the whole realm of space, and indeed wherever there is Aether, there we have the conditions which give rise to magnetic phenomena, such as those already indicated. It matters not whether it be in the atomic systems whose combinations comprise all material forms of life with which we are familiar, or whether it is in the systems of planets that revolve around their central sun, or whether it be in the constellations that fill the universe, wherever we find the Aether, there we find the conditions in that Aether which will produce all the results ordinarily produced by magnetism, or with which magnetism is associated, and it is to the application of these phenomena to our solar system that we will now turn our attention. ART. 87. _The Earth a Magnet._--If there is any fact in relation to a planet that holds good, it is that the earth, with which planet we are more intimately associated than any other, is a magnet. This truth was clearly explained by Dr. Gilbert about the year 1600 in his work on "De Magnete." Not only has the earth geographical North and South poles, but it has also magnetic North and South poles, and indeed has all the phenomena incidental to a magnet, such as magnetic dip and magnetic lines of force, as we shall see later on. We know, however, that the earth is simply one of a system of planets, which revolves with all the others of that system round its central body the sun; and the question arises, whether the earth is the only one out of all the planets that is actually a magnet. Suppose it is affirmed that the earth is the only planet which is a magnet. On what basis would such a statement be made? The only ground for making such a statement that I can see is, that we have never lived on Mars or Jupiter or Saturn, or any of the other planets, and therefore been unable to experiment on them, which reason is totally insufficient and inadequate for such a conclusion.