conditions, and therefore, when we are confronted with strange
phenomena, a knowledge of the general principles involved, will show us
in what direction to look for an explanation. Now applying this to the
present subject, we may reasonably argue, that since all physical matter
is scientifically proved to consist of the universal ether in various
degrees of condensation, there may be other degrees of condensation,
forming other modes of matter, which are beyond the scope of physical
vision and of our laboratory apparatus. And similarly, we may argue,
that just as various effects can be produced on the physical plane, by
the action of etheric waves of various lengths, so other effects might
be produced on these finer modes of matter, by etheric waves of other
lengths. And in this connection we must not forget that a gap occurs
between the "dark heat" groups and the Hertzian group, consisting of
five octaves of waves, the lengths of which have been theoretically
calculated, but whose action has not yet been discovered. Here we
admittedly have a wide field for the working of known laws under as yet
unknown conditions; and again, how can we say that there are not ranges
of unknown waves, yet smaller than the minute ultra-violet ones, which
commence the present known scale, or transcending those largest ones,
which bear our messages across the Atlantic? Mathematically, there is no
limit to the scale in either direction; and so, taking our stand on the
demonstrated facts of science, we find, that the known laws of Nature
point to their continuation in modes of matter and of force, of which we
have as yet no conception. It is therefore not at all necessary to
spurn the ground of established science to spread the wings of our
fancy; rather it affords us the requisite basis from which to start,
just as the aeronaut cannot rise without a solid surface from which to
spring.

Now if we realize that the ether is an infinitely subtle fluid,