heat ether.

"Their discoveries show that the atmospheric etheric envelope of
each etheric atom is made up of etheric atoms of different
vibratory powers. As the atmosphere of the earth is made up of
atoms of oxygen and nitrogen and argon, so that of an atom is
made up of three kinds of ethers, corresponding to three of our
senses. That it consists of five ethers, corresponding to our
five senses, as the ancient Hindus assert--who can say?

"I mention this subject of the differentiation of the ether
merely that you may not suppose that the ether is a simple
substance. For the present we will treat it as a simple
substance, but next year we will take it up as a compound one.

"This steel bar before you is not one bar, but two bars. There
is a visible bar and an invisible bar, the visible bar being made
of physical atoms, and the invisible bar of etheric atoms. The
etheric bar is invisible, but it is made of matter, the same as
the visible bar, and it is just as real, just as truly a bar as
the one we see.

"More than this. The etheric, invisible bar is the source and
cause of all phenomena connected with the bar. It is the real
bar, and the one we see is merely the shadow in physical matter
of a real bar. In shape, strength, color, in short, in
everything, it depends on the invisible one. The invisible
dominates, governs, disposes. The visible is merely its
attendant shadow, changing as the invisible, etheric bar changes,
and recording for our senses these invisible changes.