The Independent. [volume] (Honolulu, H.I.) 1895-1905, 1896-11-21
TIE x Ray, 1t rs Claimed, Is An
Old Discovery.

In the midst OF the excitement
over Roentgen's discovery, Mr..
Langley, Secretary of the Smithson-
ian Institution at Washington,
points modestly to the fact that
twelve years ago he succeeded in
causing the visible infra-red rays Of
the sola spectrum to pass through a
sheet of hard rubber. He found
also that these rays would go
through glass that was smoked so
blackly as to be perfectly opaque to
ordinary light rays. And this is not
all. By means of the wonderful in
strument known as the bolomoter
he passed moon rays through rubber
and measured their heat on the
further side.
No attempt was made to photo
graph with these rays. However,
photographs have actually been
taken recently by means of moon
rays. Lately, too, success has been
obtained in taking photographs
with the invisible infra.r red rays by
special process that has no relation
to the Roentgen idea. 1t is fact
we'll known that only a small frac-
ton of the rainbow or solar spectrum
is visible to the human eye. That
fraction consists of a few bands OF
colors, with violet at one end and
red at the other. But beyond the
violet is a region of unseen rays
which has been studied by photo
grapby; for though they produce no
impression on the retina of the eye,
they have chemical properties which
affect the Photographic plate.
However, below the red is far
more extensive region of invisible
rays and colors never seen by mortal
eye. Taking the solar spectrum on
scale that makes the visible part
OF it three feet in length, Mr.. Lang
ley has followed it into the darkness
beyond the red for a distance of
forty feet. Whereas the violet band
is toward the cold extremity of the
rainbow, the red is toward the hot
end. In fact, three-fourths of the
SUMS energy is represented by the
unseen rays beyond the red. Upon
these infra-red rays the farmer
chiefly depends for the raising of
his crops, and they are of essential
Importance to human life and all
the activities of mankind.
The nature OF the suns radiant
energy is to a great extent mystery
as yet. Only small part of it is
manifested to tho eye, and very like
ly it comprises many kinds of rays
whose activities are not now DIRE am
ed of, The X rays of Roentgen are
actually an unknown quantity, as
their name implies; the discoverer
does not pretend to say what they
are. They are termed electric, be-
cause they proceed from the mega
tive electric pole or cathode. But,
according to the theory now uni
versally accepted, sunlight itself is
an electro magnetic phenomenon.
The velocity Of light is exactly the
same as the velocity of electricity
through the same medium. Hence
it follows that electricity and light
must be movements of the same
medium-namely, the o-called lumi-
niferous ether, which occupies all
space.
The reason why so small a fraction
Of the rainbow is visible to the
human eye is that this organ is in a
sense very defective. 1t is not able
to perceive rays of light when the
light waves are very short or very
long. Above the violet these waves
become so short and rapid that the
nerve-screen which lines the eye is
not capable of registering the i'm
pressions. In like manner, the
waves below the red produce no i'm
preston upon the retina. Taking
into account the great regions of
eolors unknown to ourselves, it is