years before Hertz, on the basis of these calculations, worked out his discovery.  Again, Neptune, the outermost known 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.

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 entirely restricted to our physical body.  The importance of this line of enquiry lies in the fact that if we do possess extra-physical powers, these also form part of our personality and must be included in our estimate of our relation to our environment, and it is therefore worth our while to consider them.

Some very interesting experiments have been made by De Rochas, an eminent French scientist, which go to show that under certain magnetic conditions the sensation of physical touch can be experienced at some distance from the body.  He found that under these conditions the person experimented on is insensible to the prick of a needle run into his skin, but if the prick is made about an inch-and-a-half away from the surface of the skin he feels it.  Again at about three inches from this point he feels the prick of the needle, but is insensible to it in the space between these two points.  Then there comes another interval in which no sensation is conveyed, but at about three inches still further away he again feels the sensation, and so on; so that he appears to be surrounded by successive zones of sensation, the first about an inch-and-a-half from the body, and the others at intervals of about three inches each.  The number of these zones seems to vary in different cases, but in some there are as many as six or seven, thus giving a radius of sensation, extending to more than twenty inches beyond the body.

Now to explain this we must have recourse to what I have already said about waves.  The heart and the lungs are the two centres of automatic rhythmic movement in the body, and each projects its own series of vibrations into the etheric envelope.  Those projected by the lungs are estimated to be three times the length of those projected by the heart, while those projected by the heart are three times as rapid