Bennington semi-weekly banner. (Bennington, Vt.) 1894-1902, 1894-10-12
TROPICAL FIREFLIES
THEY FURNISH THE MOST ECoNOM-
ICAL LUMlNANT KNOWN.

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-
esque research-relating to the light afford
ed by flroaies.
This light, Professor Langley has dis
covered, is the most economical illuminant
in the world. 1t 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 90 per cent. In other words,
the consumer pays 81 for every cents
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 cold
light without waste. If a process could
be invented for producing it in large guam
titles by artifce, the discovery would be Of
enormous benefit to mankind. Incidental
ly electricity and gas would be driven out
of use for illuminating purposes. That
tho secret will be found sooner or later is
not at all unlikely. The EDotion 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 product Of
chemical combustion.
Such being the case, it ought to be prac.
ticable to reproduce the phenomenon in
the laboratory or even on q large scale.
This peculiar light termed "phosphores-
cence," has received little attention from
scientists up to date. 1t affords an attract
i've field for vestigation. The SUPPOSE
ton is that it 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, jellyflshes, ETC., not to mention
innumerable vegetable organisms, each Of
which is a tiny lantern. In the depths
swim lamp bearing fishes. On land crawl
glowworms and electrical centipeds, !"
while in the air flreflies and lightning
bugs" of many kinds disport themselves
All of this light crowded into Ol.e place
would hardly affect a thermometer.
The most brilliant light afforded by any
land animal is that of the famous FREELY
of the tropics, known as the "cucujo. F"
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 guide to the PATH also
they use them as ornaments for the dress
and hair.
1t is with these freflies that Professor
Langley conducted his experiments. They
are beetles, beginning life as grubs "Skip
jacks" or spring 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
other on the abdomen. Damp evenings are
most favorable to the light giving, the OBJ
ject of which is presumably t. attract the
sexes. The young larvae feed ,rgely on
snails, to which their bite is poisonous
The luminous organs are developed before
the insects leave the eggs.
Now, a theory formerly held was that
these flreflios 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
shono as brightly as ever after being con-
fined for 10 days in darkness. Some that
were carried all the way from Cuba to
Havre, in the pitch black hold of a 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 shone!
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 a glass re-
ceptacle. Then he dried the eggs and kept
them in that condition for long time. On
being moistened they shone. The dried
eggs were powdered in a 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 moro 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 make light equal in brilliancy to
that Of this tropical INSECT we must pro-
duce a temperature of 1900 degrees. The
freflys lamp creates no heat that can be
detected by the most delicate instruments.
Its energy is entirely expended in illumi
nation. Nature while offering object les
sons in the art on every hand, laughs at
mans efforts to initiate her in this field.
There is 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-
fled gases, but it is only plaything in the
laboratory.
There are good many kinds of flreflies
In the world. Those which give an inter
mittent light are popularity distinguished
rs lightning bugs" The glowworm Of
literature is the female of European fire.
fly. She never acquires wings. Her lu-
minous substance is q soft yellowish
grease, extending in a thin layer along
the inner sides of the abdomen. A few
glowworms exist in the United States, but
tbay mn, roro Tho common, n,o0inc Of