Chicago eagle. [volume] (Chicago, Ill.) 1889-19??, 1894-12-29
CHEAPEST OF ALL LIGHTS.
That Shown by Fircflics - scientific
Experiments In Way of Imitation.


Experiments In Way of Imitation.
One of the prctticst sights of a sum-
mcr evening In the country Is u meadow
covered with u swarm of fitting fire.
flies. Many intensely practical pcO-
pie have laughed ut any suggestions
that this FREELY light could be utilized
In any way by man. Yet scientists
have long been ut work on the problem.
and one of the number. Secretary
Langley, of the Smithsonian 1nstitu-
ton. has arrived at some startling con-
illusions. The light shed by these in
sects, says the Boston Journal, Is the
most economical illumlnant In tho
world. 1t has no waste and no ever
running meter. Moreover, 1t Is 100
times as cheap as gas, which means
that one pays a dollar for a cents
worth Of light, and even with cleo.
tricity the waste Is enormous. With
the FREELY there Is no waste by the pro-
ductlon of heat. This may seem rather
strange to those who insepnrably con-
meet light with some degree Of heat
manifestation, and this "cOld llghtS
II such 1t might DC called, would be Pc
culiarly adapted to hot summer even
ing. 1t Is probably simply the result
of chemical action which produces
phosphorescence. 1t Is produced ut
one.fOurth. hundrcdth Of the cost Of
energy represented In candle flame,
and IL supposed to come from the slow
combustion Of a material secreted by
the nervous organism of the insect.
The temperature OF the light.giving Or
gans Is the same as that of other parts
Of the body.
In Professor Langley's experiments
he took the insects, kept them In the
dark all the time, preserved their eggs
long time, ana ground the dried sub.
stance to powder. In all these cases
the application of moisture produced u
light, proving the chemical origin OF
the phenomenon. To produce light
of equal brilliancy artiiicially would
require n temperature of ut least 1000
degrees. The most brilliant of the $50
varieties of animal life capable Of
producing light of this character IL
the "cucujo." the famous FREELY of the
tropics. Thirty-eight of these yield one
candle power. Tho natives of Cuba
confinc them In paper lanterns, and
they have been used to take photo.
graphs by Il two-minutc exposure Of
bromide plates. These insects, or
beetles. to speak exactly, We're used by
Professor Langley In experimenting.
They begin life as grub, and are va
riO,isly called "skip-jacks," or "spring-
tails" Damp evenings seem to be tho
most favorable time to observe their
habits, as then they shine most brill.
iantly. Nature having produced this
most economical light. which In the
most exaggerated instance cannot DO
made to affect the Wost delicate Their.
mOmcter, seems to laugh ut the feeble
efforts Of man to follow her plan. 1t
Is true that the Gcissler tube, a play
thing of the laboratory will produce
light without heat, but 1t is incapable
of practical production. Scientists be-
lieve that ere long the secret of the Won
derful light, which has been proved I'M
like the luminous calcium sulphide
paint Of commerce, will be discovered,
with result as revolutionary In the
world of illumination as that caused by
electricity.