Evening star., 1940-06-22
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Field. Laboratory
And Study
By Thomas r. Henri.

And Study
By Thomas r. Henry.
The flashing Of field Of nrefiies, one
Of the loveliest phenomena Of nature on
summer evening, is an expensive show.
This is pointed out in the annual re-
port Of the Smithsonian Institution by
DR.. N. S. Rustum Maluf of the Osborn
Geological Laboratory of Yale University.
For two generations one of the ideals
Of science has been to produce arti-
ficially cold Naturalization confined
entirely to those wave lengths to which
the retina Of the human eye is sensitive
and without any energy wasted in the
form Of heat or invisible light. Could
the ideal be attained with the same ex-
penditure of fuel and power as is re-
quired for light production at present
the worlds bills for illumination would
be decreased enormously.
Actually the FREELY has attained this
ideal In one direction. 1t emits only
visible light Chemists can even dupli-
cate the process to a certain extent.
Naturally great deal of research has
been devoted to the Ight-emitting mech
anism, physical and chemical, of the in
sects. The findings have been rather
disappointing, so far as practical appli-
cation is concerned. DR.. Maluf points out
The phenomenon Of luminescense is
widespread IN nature. It is found among
crustaceans, centipedes and few other
insects. In each case it is a chemical
process, developed by the animals them
selves in the course of evolution and sur
Vlval OF the fittest, and finely adjusted
to the needs of the individual species.
But IN no case, DR.. Maluf says, is 1t to
pe considered cheap process, as
some physicists have thought before in
tensive study of the factors involved
The luminescense of the fref1y. DR..
Maluf points out, is due to the oxidation
that is, the burning-of a chemical
substance, luciferin. This reaction. in
turn depends upon a catalyst, a SUBJ
stance which activates a chemical reac-
ton without taking part in it-knoyn
as luciferase. The same phenomenon
can be brought out by appropriate mix
lures Of luciferin, luciferase and oxygen
IN test tube at the proper temperature.
All these experiments have shown that
IL Is, IN one sense, very wasteful proc
ess considering the amount of oxygen
necessary. 1t is far less efficient than
most means OF producing artificial LIGHT
known TO mani per cent compared
WIN the 454 per cent .of the carbon
nlament; l7.l7 per cent of the acetylene
flame, or 60 per cent OF the sodium arc
light. To illuminate houses or streets
with FREELY light would be a very exnen.
sive procedure indeed.
Dr. Maluf quotes calculation that
"an area OF firehy light six feet in diam
eter on the ceiling of room nine feet
nlgh would give ample illumination for
reading or drawing on a table three feet
nigh" This would hardly interest an
Illuminating engineer, he points out. The
light can be used in an emergency Mai.
Gen. W. G. Gorgas during the Spanish
american War is reputed to have used
the light from bottle Of frenys to per-
form an emergency operation. But the
average householder would rebel At the
monthly bills.
Inc actual light from a single f,ref1v
Is very minute, indeed, averaging little
more than 25/1 .000ths Of candle
power. The combined courtship efforts
OF whole field full Of the insects hardly
would light single room enough for
sewing or reading The insect will
sometimes glow steadily with a light as
low as 2/lo0 Oooths of a candlepower in
intensity.
from another point of view, however,
tne nrefly or any other sort of lumines-
cent animal is very efficient indeed. A
good part Of the total radiation from
any man-made source of Ight-or for
tnat matter from the sun or the moon
Is invisible. Some of it is in the in
Visible ultraviolet. A lot more of 1t is
IN the invisible infrared, observable only
as neat. Possibly the FREELY produces
some heat in its light production, but it
Is TOO little to be measured. It Is safe
to say, DR.. Maluf says, that within a
tiny fraction, 100 per cent of the radia-
ton produced is in the visible spectrum
most of it Of shorter wave lengths than
those which produce the sensation of
blue light. This is by far the highest
emclency known to science.
Among firef1ies flashing is essentially
courtship phenomenon, yet there is
no discernible difference between the
quality Of the light of male and female
insects. What actually happens, DR..
Maluf explains, is that the flash of the
female In response to the signal of the
male Is timed almost exactly at trif1e
over two seconds. The male Is instinc-
lively aware of this time interval, so that
ne, does not become confused with the
signals Of other males
In a large group of the insects the
flashes OF the two sexes tend to become
synchronized-a phenomenon which has
excited the wonder of naturalists.
Suggests Grounds for
DepOrting Bridges.