between the dark heat group and the Hertzian group, but mathematically
there is no limit to the greatness or smallness of the waves, and the
scale may be prolonged indefinitely in either direction. Nor is this to
be wondered at; for if we consider that vibration is not a progress of
individual particles from one place to another, but the alternate rising
and falling of the substance at the same point, and that the ether is a
homogeneous and universally present substance, it is obvious that there
is nothing to limit the minuteness or the greatness of the intervals at
which the rising and falling will occur. Therefore we have an unlimited
field for our imagination to play about in. Then, if we further reflect
that all forms are built up of denser or finer aggregations of ether,
and that what determines the generic form of anything is its cosmic
soul, or the generating principle of the _class_ to which it belongs, it
follows that this soul must have a corresponding form, however
inconceivably fine may be the etheric condensation which thus
differentiates it from other souls, and prevents it from all being
mixed up together in an indistinguishable mass. If now, we combine these
two facts, that the soul of anything must have a form, however fine, and
that there is no limit either to the greatness or the minuteness of
etheric vibrations, we can draw certain deductions from these premises.

It is an established fact of ordinary science that, however closely
particles of any substance may seem to cohere, they are in reality
separated by interstices through which etheric waves can penetrate.

The principle may be illustrated by the power of the X-rays to penetrate
apparently solid bodies, such as iron. Then, if we combine with this the
fact, that there is no limit to the minuteness of etheric waves, we see
that however fine may be the particles constituting any form, it is
always possible to have etheric waves still finer and thus able to