rom the
sun. As for the fixed stars, they are so far separated from us that, at
the present rate of motion of the solar system in its drift through
space--500 millions of miles in a year--it would take not less than
40,000 years to reach the nearest star among its neighbours, while for
the more remote ones millions of years must be reckoned. The huge space
separating these masses is practically devoid of matter; it is a vacuum.

THE ETHER IS CONTINUOUS.

The idea of continuity as distinguished from discontinuity may be gained
by considering what would be made visible by magnification. Water
appears to the eye as if it were without pores, but if sugar or salt be
put into it, either will be dissolved and quite disappear among the
molecules of the water as steam does in the air, which shows that there
are some unoccupied spaces between the molecules. If a microscope be
employed to magnify a minute drop of water it still shows the same lack
of structure as that looked at with the unaided eye. If the magnifying
power be the highest it may reveal a speck as small as the
hundred-thousandth part of an inch, yet the speck looks no different in
character. We know that water is composed of two different kinds of
atoms, hydrogen and oxygen, for they can be separated by chemical means
and kept in separate bottles, and again made to combine to form water
having all the qualities that belonged to it before it was decomposed.
If a very much higher magnifying power were available, we should
ultimately be able to see the individual water molecules, and recognize
their hydrogen and oxygen constituents by their difference in size, rate
of movements, and we might possibly separate them by mechanical methods.
What one would see would be something very different in structure from
the water as it appears to our eyes. If the ether were similarly to be
examined through higher and still higher magnifying powers, even up to
infinity, there is no reason for thinking that the last examination
would show anything different in structure or quality from that which
was examined with low power or with no microscope at all. This is all
expressed by saying that the ether is a continuous substance, without
interstices, that it fills space completely, and, unlike gases,
liquids, and solids, is incapable of absorbing or dissolving anything.

2. MATTER IS LIMITED.

There appears to be a definite amount of matter in the visible universe,
a definite numb