as those projected by the lungs. Consequently
if the two sets of waves start together the crest
of every third wave of the rapid series of short waves
will coincide with the crest of one of the long waves
of the slower series, while the intermediate short
waves will coincide with the depression of one of
the long waves. Now the effect of the crest of
one wave overtaking that of another going in the same
direction, is to raise the two together at that point
into a single wave of greater amplitude or height
than the original waves had by themselves; if the reader
has the opportunity of studying the inflowing of waves
on the seabeach he can verify this for himself.
Consequently when the more rapid etheric waves overtake
the slower ones they combine to form a larger wave,
and it is at these points that the zones of sensation
occur. If the reader will draw a diagram of two
waved lines travelling along the same horizontal line
and so proportioned that the crest of each of the large
waves coincides with the crest of every third wave
of the small ones, he will see what I mean: and
if he then recollects that the fall in the larger
waves neutralizes the rise in the smaller ones, and
that because this double series starts from the interior
of the body the surface of the body comes just at
one of these neutralized points, he will see why sensation
is neutralized there; and he will also see why the
succeeding zones of sensation are double the distance
from each other that the first one is from the surface
of the body; it is simply because the surface of the
body cuts the first long wave exactly in the middle,
and therefore only half that wave occurs outside the
body. This is the explanation given by De Rochas,
and it affords another example of that principle of
mathematical sequence of which I have spoken.
It would appear that under normal conditions the double
series of vibrations is spread all over the body,
and so all parts are alike sensitive to touch.

I think, then, we may assume on the basis of De Rochas’ experiments and others that there are such things as etheric vibrations proceeding from human personality, and in the next chapter I will give some examples showing that the psychic personality extends still further than these experiments, taken by themselves, would indicate—in fact that we possess an additional range of faculties far exceeding those which we ordinarily exercise through the physical body, and which must therefore be included in our conception of ourselves if we are to have an adequate idea of what we really are.

**SOME PSYCHIC EXPERIENCES**