16). If we could
now run all these coloured rays together again, we should simply
reproduce white light. We can do this by catching the coloured band in
another prism, when the light now emerging will be found to be white.
Every part of that spectrum consists of homogeneous light, _i.e._ light
that cannot be further split up. The way in which the white light is so
unravelled by the prism is this: As the light passes through the prism
its different component coloured rays are variously deflected from their
normal course, so that on emerging we have each of these coloured rays
travelling in its own direction, vibrating in its own plane. It is well
to remember that the bending off, or deflection, or refraction, is
towards the thick end of the prism always, and that those of the
coloured rays in that analysed band, the spectrum, most bent away from
the original line of direction of the white light striking the prism,
are said to be the most refrangible rays, and consequently are situated
in the most refrangible end or part of the spectrum, namely, that
farthest from the original direction of the incident white light.
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