ter and in Ether--Matter as a transformer
of Energy--Elasticity--Vibratory rates and
waves--Density--Heat--Indestructibility of
Matter--Inertia in Matter and in Ether--Matter
not inert--Magnetism and Ether waves--States
of Matter--Cohesion and chemism affected by
temperature--Shearing stress in Solids and in
Ether--Ether pressure--Sensation dependent upon
Matter--Nervous system not affected by Ether
states--Other stresses in Ether--Transformations
of Motion--Terminology.

A common conception of the ether has been that it is a finer-grained
substance than ordinary matter, but otherwise so like the latter that
the laws found to hold good with matter were equally applicable to the
ether, and hence the mechanical conceptions formed from experience in
regard to the one have been transferred to the other, and the properties
belonging to one, such as density, elasticity, etc., have been asserted
as properties of the other.

There is so considerable a body of knowledge bearing upon the
similarities and dissimilarities of these two entities that it will be
well to compare them. After such comparison one will be better able to
judge of the propriety of assuming them to be subject to identical laws.

1. MATTER IS DISCONTINUOUS.

Matter is made up of atoms having dimensions approximately determined to
be in the neighbourhood of the one fifty-millionth of an inch in
diameter. These atoms may have various degrees of aggregation;--they may
be in practical contact, as in most solid bodies such as metals and
rocks; in molecular groupings as in water, and in gases such as
hydrogen, oxygen, and so forth, where two, three, or more atoms cohere
so strongly as to enable the molecules to act under ordinary
circumstances like simple particles. Any or all of these molecules and
atoms may be separated by any assignable distance from each other. Thus,
in common air the molecules, though rapidly changing their positions,
are on the average about two hundred and fifty times their own diameter
apart. This is a distance relatively greater than the distance apart of
the earth and the moon, for two hundred and fifty times the diameter of
the earth will be 8000 x 250 = 2,000,000 miles, while the distance to
the moon is but 240,000 miles. The sun is 93,000,000 miles from the
earth, and the most of the bodies of the solar system are still more
widely separated, Neptune being nearly 3000 millions of miles f