The herald. [microfilm reel] (Los Angeles [Calif.]) 1893-1900, 1894-06-24
TROPICAL TIREFLIES
THEY FURNISH THE MOST scoNoM-
IcAL LUMl,SkNT KNOWN.

a Gold Light Without Waste-HoW this
People Of Cuba Make Use of the "Cucujb.'
some Interesting Facts About These Gu
rious Insects.
Science under Uncle Sans auspices has
done no more important work than has
been accomplished in the study of insects
In that branch of the animal creation Sec
rotary Langley of the Smithsonian institu.
ton has made perhaps the most pictur-
esuue MISUNDERSTANDING to the light afford
ed by fref1ies.
This light, Professor Langley has dis
covered, is the most economical illuminani
In the world. II is 100 times as cheap as
gas-that is to say, there is no waste,
whereas the waste in burning gas or lamps
is more than SO per cent. In other words,
the consumer pays 81 for every cent S
worth of light he gets. With electricity
the waste is less, but still enormous. The
freely light expends no energy in the shape
of heat.
So here is what might be termed a cold
Hight without waste. If a process could
be invented for producing it in large guam
titles by artifice, the discovery would be of
enormous benefit to mankind. Incidental
ly electricity and gas would be driven out
of use for illuminating purposes. That
the secret will be found sooner or later is
not at all unlikely. The notion formerly
held that the light was part and parcel of
the life Of the FREELY has been exploded. 1t
is now believed to be simply a product of
chemical combustion.
Such being the case, it ought to be prac-
tioable to reproduce the phenomenon in
the laboratory or even on a large scale.
This peculiar light. termed sphosphores-
oence," has received little attention from
scientists -aedabe. 1t affords an attract
i've field Ior investigation. The suppose
ton Is thai 1t is made by the slow combus-
ton of material secreted under the control
of the nervous system of the insect. 1t is
produced at one four-hundredth of the
cost of energy expended IN a candle flame.
Nothing Is lost in the shape of heat, the
light giving organs having the same tenn
perature as other parts Of the animal.
More than $50 families of animals on
land and in water, embracing tens of
thousands of species, produce such light.
They Yield enough of it to illuminate Lon
don, Paris and New York. The surface
of the ocean is alive with luminous crus-
taceans, jellyfishes, ETC., net to mention
1nnumezaEfe vegetable organisms, each of
which is a-tiny lantern. In the depths
swim lamp bearing fishes. On land crawl
glowwerms and electrical centipeds,
while In the air Grefies and lightning
bugs of naay kinds disport themselves.
Ali of bhis light crowded into one place
would hardly affect thermometer.
The most brilliant light afforded by any
land animal Is that of the famous FREELY
of the TROPICS, known as the ''cucujo."
Thirty eight of them yield one candle pow
er. Photographs have been printed by
two minute exposure of bromide plates to
their Illumination. People in Cuba con-
fine them In paper lanterns for going
about the country at night or for indoor
lighting Sometimes they attach one of
the insects to each foot for travelling in the
dark to serve as a guide to the path; also
they use them as ornaments for the dress
and heir.
1t Is with these frefies that Professor
Langley conducted his experiments. They
are beetles, beginning life as grubs. Skip
jacks, or ''spFing tails, they are some
times called, because, when placed on their
backs, they jump over with a clicking
sound. A small species of the same family
Is found in Florida and Texas They have
two luminous spots on the thorax and an
other on the abdomen. Damp evenings are
most favorable to the light giving, the OBJ
ject of which is presumably to attract the
sexes. The young Larvae feed largely on
snails, to which their bite is poisonous.
The luminous organs are developed before
the insects leave the eggs.
Now, theory formerly held was that
these freflies stored up light in the day
time for emission at night, as is done by
the SO called luminous paint" of calcium
sulphide. But it was found that they
shone as brightly as ever after being con-
fined fer 10 days in darkness. Some that
were carried all the way from Cuba to
Havre, in the pitch black hold of vessel,
were brilliant on their arrival A more
striking disproof, however, was afforded
by batch OF larvae Matched in the dark
from eggs laid in the dark in piece of
rotten wood, the young insects being kept
in darkness for the first six months of
their lives. They shonel
Professor Langley decided that the light
did not depend on the vital principle of
the insect He found that the eggs became
luminous on being shaken in glass re-
ceptacle. Then be dried the eggs and kept
them in that condition for long time. On
being moistened they shone. The dried
eggs were powdered in q mortar, but they
gave light on being wetted. The beetles
themselves, 10 hours after being killed by
electricity, were still luminous. So the
professor infers that nothing more than a
chemical combustion is concerned in the
manufacture Of this cheapest light" He
thinks there is hope that we may be able
to reproduce it some day.
TO mako light equal in brilliancy to
that of this tropical insect we must pro-
duce temperature of 2, 600 degrees. The
fireay's lamp creates no heat that can be
detected by the most delicate instruments.
Its energy is entirely expended in illumi-
nation N3ture while offering object les
sons in the art on every hand, laughs at
mans efforts TO initiate her in this field.
There is a device known as "Geissler's
tube, " by which much greater light than
that OF the FREELY is made without any heat,
electric sparks being flashed through rari-
fed gases but it is only plaything in the
laboratory.
There are good many kinds of firefiies
IN the world. Those which give an inJer
Inittent light are popularity distinguished
as lightning bugs" The glowworm Of
literature is the female of European fire.
fly. She never acquires wings. Her lu-
minous substance is soft yellowish
grease, extending in thin layer along
the inner sides of the abdomen. A few
glowwornls exist in the United States, but
they are rare. The common frefies of
Ghis country have wings, females as well
as males. The larvae are stout bodied and
grublike, found under stones and logs.
They yield some light. Star.