Los Angeles herald., 1907-01-27

by a man in the gallery, who places sheets of
brightly-colored gelatine before a limelght
whose beams are thrown on the stage.
Now. / think that many people, who are
not acquainted with the true laws Of light
and color, believe that the light in the above
cases is colored by passing through the glass
or gelatine, just sken of yarn is colored
by passing it through a dye.vat, or as the
water in the vat is colored when the dye is
added.
In other words. think il is quite natural
and usual to imagine that something has
been added to the beam of lght-that it has
been dyed red or blue or green by taking up
some color from the glass.
But it can be easily shown that this idea is
wrong-that nothing has been added to the
light-but that something has been taken
from it by its passage through the glass.
Ii narrow beam of sunlight, coming from
small hole in the shutter of darkened
room, is made to fall upon a triangular
prism of glass, like those which are some
times used as ornaments on chandeliers, the
beam is not only bent from its course, but
spread out, SO that if received upon white
wall 1t makes long streak instead of 9
small spot.
Furthermore, this streak is brightly color
ed. One end is red, then come orange, vel
low, green, blue, and, at the other end, violet
One color shades into the next, and it is i'm
possible to say how many different tints ther,
are.
In this case the light has been colored by
passing through colorless piece of glass
and different parts of the beam have taker
| different shades.
| Now, if this many-colored beam is passed
through lens or magnifyingglass, which
| bends the different parts of the beam to
gether the long, colored streak the wal
is replaced by small white spot, such as tn,
sunbeam would have formed if it had no
been interrupted at all.
This experiment shows that white light il
kinds of light of different colors.
Now, what happens when the beam fall
upon the red glass, is simply this:
OF the many kinds of light of which tn,
white light is composed, only few are al
lowed to pass through the glass. The kin,
of red and orange, and some yellow. Mos
of the colors which do get through al,
greatly weakened, but few shades of ret
retain nearly their original strength.
pertinent with the prism, and placing tn
red glass in the path of the light, either be
fore or behind the prism.
As the glass is interposed, more than hal
of the colored streak, including the greer
blue and violet portions, disappears.
In the same way, other colored glasses de-
troy other portions of the image, and r.
duce it to band of greater or less width
Some kinds of glass and other transp;
rent substances give an image consisting {
two or more colored bands, separated b
dark spaces. But it is noticed that any pa
ticular color-,a certain shade of red, fo
example-is always found at the same. poin
of the wall, if it is present at all, whethe
red glass, blue glass or no glass whateve
is interposed.-
In other words, the colored glass can onl
cut off or weaken the different kinds Q
light, but it cannot change the green to blu
Nor can it add anything to the light. n
kind of light is found after the glass ha
been interposed which was not there before
but some kinds which were present hav
vanished.
What has become of them?
They are commonly said to have been al
sorbed. They have entered the glass, but il
the passage through it they have been gradu