<h2><SPAN name="CHAPTER_XIV" id="CHAPTER_XIV"></SPAN>CHAPTER XIV</h2>
<h2>HOW WE PRODUCE COLOUR</h2>
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<div><span class="pagenum"><SPAN name="Page_136" id="Page_136"></SPAN></span></div>
<h3><i>THE SCRIBE'S NOTE ON CHAPTER FOURTEEN</i></h3>
<div class="blockquot"><p>Colour is merely a sensation in the brain.</p>
<p>What the electrons really produce are
æther waves, and these give rise to the sensations
of colour.</p>
<p>However, the electrons may claim to produce
colour in the same sense as we savages
produce pain in fellow-men by firing rifle-bullets
at them.</p>
<p>The electron explains how some objects
appear white, while others are red, and so
forth.</p>
<p>It explains also how electrons produce
artificial light.</p>
<p>The electron twits man upon his ridiculously
wasteful processes of obtaining artificial
light.</p>
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<p><span class="pagenum"><SPAN name="Page_137" id="Page_137"></SPAN></span>
In the preceding chapter I have been telling
you how we electrons produce waves in the
æther ocean. I pointed out that if we make
the waves follow each other at too slow or too
fast a rate they fail to affect man's eyes.</p>
<p>It may seem strange to you that only a
very small range of our æther waves should
affect man's visionary apparatus. Of course
this limitation lies beyond our province; we
can produce endless variety of æther waves—it
is man's organs which fail to appreciate the
bulk of these. However, there is plenty of
variety in the sensations which we can produce
in man. If we make the waves follow
each other at a certain speed, man says he
has the sensation of <i>red</i>. If we move faster,
he speaks of <i>orange-colour</i>, and as we increase
our speed he names his further sensations as
<i>yellow</i>, <i>green</i>, <i>blue</i>, and <i>violet</i>. Then if we
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combine all these waves—that is, if we produce
them all at one time—he says he has the
sensation of <i>white</i>. If we produce none of
these waves, he calls the result <i>black</i>.</p>
<p>While we electrons are very versatile, our
actions are dependent in a great measure
upon circumstances. For instance, if an electron
is acting as a satellite to one particular
kind of atom, its rate of revolution around
that atom may be very different from that of
an electron similarly attached to another kind
of atom. We electrons are all identical, but
the speed of revolution is determined by the
kind of atom. The reason is very simple;
electrons revolve around some atoms at a
much greater distance than they would
around other atoms. Those making only the
smaller orbits not only get around their
atoms in less time, but they are also travelling
at a greater pace. It is this fact which
enables the electrons to produce the various
wave-lengths which stimulate the different
colour sensations in the brain of man.</p>
<p>I think you will have no difficulty in seeing
how it is that we come to produce such a
variety of wave-lengths—in other words,
how we are able to make the waves follow
<span class="pagenum"><SPAN name="Page_139" id="Page_139"></SPAN></span>
each other more or less rapidly. You will
understand that we do not produce colours;
we merely make various waves in the æther,
and these waves excite the colour sensations
in man. I mention this simple fact, because
I hear many people speaking of our æther
waves as "coloured rays," which, of course, is
quite a ridiculous description.</p>
<p>Suppose some of those waves which give
rise to the red sensation happen to fall upon
a lump of matter which contains only electrons
capable of producing waves that affect the
green sensation. What will happen? There
will be no response, and the object, although
viewed by "red light," will appear black.</p>
<p>If an object, such as the white paper upon
which my scribe is recording my story, contains
a variety of atoms with electrons capable of
revolving at all the different rates which
produce colour sensations, then when "white
light" falls upon the object it appears white
(all the colour sensations combined). If, on
the other hand, a "red light" only falls upon
it, then only the electrons capable of responding
to that rate of wave will be set in motion,
and the object will appear red, and so on
with the other rates of æther waves.</p>
<p><span class="pagenum"><SPAN name="Page_140" id="Page_140"></SPAN></span>
So far I have been telling you what happens
when different waves of light fall upon us.
Now I shall endeavour to explain how man
has caused us to produce artificial light. At
present all man's methods in this direction
are dependent upon making some substance
so hot that it becomes incandescent. Even
his most modern methods seem to us to be
ridiculously wasteful and most roundabout. I
shall speak only of the electric glow lamp, as
I have had some experience in connection
with this.</p>
<p>On one occasion I had been taking part
in a regular forward march from copper atom
to copper atom in a conducting wire. I had
no idea of the purpose of our march till I
suddenly found myself handed over to some
carbon atoms, who were in a very lively state
of vibration. We had much more difficulty
in making our way through this substance,
and it was the passive resistance offered to the
advance of the electrons who had preceded
me that had driven the carbon atoms into
this state of great excitement. In our march
through the copper conductor we had been
offered very little resistance, so that we had
left the copper atoms in peace—at least man
<span class="pagenum"><SPAN name="Page_141" id="Page_141"></SPAN></span>
could not detect easily any excitement (heat).
But so long as our forced march was maintained
among the carbon atoms, so long did
the high temperature exist.</p>
<p>You will understand I and the other marching
electrons did not produce the waves of
light sent out by the glow lamp. What we
did was to set the atoms of carbon into
a rapid vibratory state, and they in turn
caused their satellite electrons to hasten their
pace. Some electrons produced one rate of
waves, and some another rate, but by the
time the carbon was incandescent there were
electrons sending out all the variety of wave-lengths,
the combination of which produces
the sensation of white.</p>
<p>I have accused man of adopting very wasteful
processes, so I had better explain the
matter. In the preceding description of what
is occurring in an electric glow lamp, I have
spoken only of those æther waves which
constitute light. But there are myriads of
electrons in the carbon of the glow lamp
that never attain the requisite speed to produce
those waves; they revolve around their
atoms at too slow a rate. They certainly
disturb the æther, but the crests of the waves
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are so far apart that they do not affect the
eyes of man. The business of these waves
is to set up heat in the bodies upon which
they fall. You may be surprised to know
that in this contrivance of man, called an
electric glow lamp, and, indeed, in all his
other artificial light-producers, he causes far
more electrons to produce radiant heat than
the desired light waves. A most wasteful
process!</p>
<p>Man has a long way to travel yet before
he succeeds in producing artificial light by
a reasonable process. Indeed I doubt if any
of you can realise, as we do, how exceedingly
stupid the existing methods are. Think for
a moment of the glow-worm, in which we
electrons produce light without setting up
any wasteful heat waves. There is a strong
contrast between this peaceful plan and that
of the excited carbon atoms. When will man
succeed in discovering this secret of ours?</p>
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