--here near together, there far apart, always the
same number and the same relative distance, when the same light
and prism are used. What new alphabets to new realms of knowledge
are these! Remember, that what we call colors are only various
numbers of vibrations of ether. Remember, that every little group in
the infinite variety of these vibrations may be affected differently
from every other group. One number of these is bent by the prism
to where we see what we call the violet, another number to the
place we call red. All of the vibrations are destroyed when they
strike a surface we call black. A part of them are destroyed when
[Page 29] they strike a substance we call colored. The rest are
reflected, and give the impression of color. In one place on the
flag of our nation all vibrations are destroyed except the red; in
another, all but the blue. Perhaps on that other gorgeous flag, not
of our country but of our sun, the flag we call the solar spectrum,
all vibrations are destroyed where these dark lines appear. Perhaps
this effect is not produced by the surface upon which the rays fall,
but by some specific substance in the sun. This is just the truth.
Light passing through vapor of sodium has the vibrations that would
fall on two narrow lines in the yellow utterly destroyed, leaving
two black spaces. Light passing through vapor of burning iron has
some four hundred numbers or kinds of vibrations destroyed, leaving
that number of black lines; but if the salt or iron be glowing gas,
in the source of the light itself the same lines are bright instead
of dark.

Thus we have brought to our doors a readable record of the very
substances composing every world hot enough to shine by its own
light. Thus, while our flag means all we have of liberty, free as
the winds that kiss it, and bright as the stars that shine in it,
the flag of the sun means all that it is in constituent elements,
all that it is in condition.

We find in our sun many substances known to exist in the earth,
and some that we had not discovered when the sun wrote their names,
or rather made their mark, in the spectrum. Thus, also, we find
that Betelguese and Algol are without any perceivable indications
of hydrogen, and Sirius has it in abundance. What a sense of
acquaintanceship it gives us to look up and recognize [Page 30] the
stars whose very substance we know! If we were transported thither,
or beyond, we should not be altogether strangers in an