mathematician Clerk-Maxwell had calculated all particulars of these waves twenty-five years before Hertz, on the basis of these calculations, worked out his discovery. Again, Neptune, the outermost planet of our system, was discovered by the astronomer Galle in consequence of calculations made by Leverrier. Certain variations in the movements of the planets were mathematically unaccountable except on the hypothesis that some more remote planet existed. Astronomers had faith in mathematics, and the hypothetical planet was found to be a reality.

Instances of this kind might be multiplied, but as the French say, "a quoi bon?" I think these will be sufficient to convince the reader that the invariable sequence of Law is a factor to be relied upon, and that by studying its working under known conditions we may get at least some measure of light on conditions which are as yet unknown to us.

Psychic Phenomena

Let us now pass on to the human subject and consider a few examples of what is usually called the psychic side of our nature. Walt Whitman was quite right when he said that we are not all included between our hat and our boots; we shall find that our modes of consciousness and powers of action are not