Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1874-02-26
The Secret OF Color.

Inc SKY IS Dlue, 50 are water ana Ice IN
large quantities, but take a small piece of
ice, a few drops of water, room fun of
air, and the color has disappeared. What
has become of it?
Shall | tell you the secret? Well the
rays which come from the sun are of
three kinds, the heat rays, the chemical
rays and the light or color rays. These
last are seven in number, corresponding
to the seven colors of the rainbow.
Now when the sun shines on water
first the heat rays are absorbed, and the
water is warmed by them. Then of the
light rays, the most quickly undulating
red rays are taken IN first, then the yellow,
then the green, then the blue and violet.
The blue and violet are the last to be alb
sorbed. This is why caves on the surface
of the sea, which are lighted only by rays
which have come through the water, al
ways appear of beautiful blue color,
like the Sapphire Grotto, at Capri, in
Italy.
If the water is deep enough, as in the
ocean, the blue and violet rays also
should be absorbed and if that were so,
the sea would appear as black AS ink
But 1t never does appear quite so dark as
this. Why?
Tyndall has shown that the color of
both water and air is largely caused
by the light reflected by floating sub
stances, too small to be usually noticed.
When he was on his way to Algers to
observe an eclipse of the sun, he collect
ed water in bottles from different parts Of
the Atlantic Ocean, from light green to
dark blue
When he returned home he examined
these specimens by passing ray OF light
through them in "A dark room, and nc
found that there was most dust in the
water that he had marked bright green
it showed, Of course, no color in the
bottle-and that which he had marked
indigo blue was the purest.
From similar experiments il is found
that warmth promotes the absorption of
the other color-rays, so that the blue tint
of the ocean, which is the last to be taken
in, is deeper near the equator and in the
tropics than elsewhere. Yet even here
Tyndall found that if he sunk a white
china plate a little way in thesea, it made
the water above it appear green.
The same is the case with clear ice. 1t
appears green or blue, according as the
light is able to penetrate it.
The water of lakes is sometimes thought
to obtain its blue color from the reflection
Of the sky, hut this is very seldom the
case. In some of the lakes Of Switzer-
land and in the geysers of Iceland the
water is tinted blue BY Iodine and other
chemical substances.
On the other hand, the azure of the sky
is probably due to water. AS even New
ton thought, it is the reflection Of light
from minute drops or bubbles OF water
contained in the atmosphere which pro
duces this tint. Tyndall ascribes the
dark blue Of starry night to the suns
rays, which are still reflected in some
measure from the PARTICLES in the air II
it were not for these, the space around our
earth would always appear jet black, as
the sky above him would look to an IN
habitant of the moon, which has no at
mospherc.
If light, instead of being reflected, is
seen through the dust or vapOr OF the air,
it appears red instead Of blue. Hence
the sun assumes its golden or reddish hue
when rising or setting, because It's rays
then pass through the thicker vapors
which are near the earth. His solar mai
esty also looks red in the face when
looked at through fog or through steam.
II is thus the Impurity Of the air near the
earth which causes the beautiful golden
light of evening.
We cannot but be struck with wonder
and admiration when we reflect with what
variety of delightful and harmonious
colors this earth is deckcd. Nor can We
fail to perceive in the secret OF color
token of the benevolcnce Of the Creator,
who has so arranged this world as thus to
give constant pleasure and instruction TO
His observing creatures Youths c +.
paHt0a
The latest agonizing joke" While
there's life there's soap" Washerwomen
will please take notice.
rTttr- too lraftla ia the only sinner that