The Washington herald., 1922-06-11

at night, such as sign posts. gates.
river beacons. life buoys and the
ater exits. This has been mainly
in England. Some people have
thought this to be the principle
back of a practical form OF inor-
ganic cold light. II such paint
could be vastly improved in bright
ness. the vision of life at night in
some far-off day-no one can tell
just how far off-allows the imaEi-
nation to conjecture up rather sur
prising fancies.
Houses might then be illuminated
without the need of internal fix
lures. Shutters for the windows
which could be coated with the
phosphorescent substance might. by
being thrown open during the day.
allow the chemical coating to store
up light from the sun. SO that when
night came it would simply be nee
'sssary to close the shutters in or
der to illuminate the rooms.
When bedtime arrived the shut
teTs might again be thrown open,
thus Illuminating the grounds and
surroundings during the hours of
olNNps anu NHt
of light against burglary.
Responsive to Rays.
The chemical compound known as
zinc sulphide may be prepared both
in fluorescent and phosphorescent
form. 1t is very responsive to the
rays which are constantly emanat-
ipU from cOmnoupdS ~ rodinn, If
comparatively minute amount of
radium salt is mixed with the zinc
salt the latter will glow continu-
ously with a degree of brightness
corresponding to the proportion of
contained radium. This Is the self
luminous paint that is used for illu-
minatfng clock faces, watch dia's
and compass needles. 1t is totally
different from the phosphorescent
paint already mentioned. 1t is re-
stricted in use because of the ex-
cessive cost of radium.
If. however, there were some
cheap element, having equivalent
radioactive properties to the ex-
pensive radium. a wide possibility
for making a commercially useful
cold light would be opened.
Thus far has the quest for inor-
ganic cold light proceeded The
other phase of the great problem.
organic cold light. is under an
equally intense investigation. This
is the biological aspect of the case.
The animal organisms that produce
illumination are here undergoing
investigation.
FirefIies and Shell Fish.
OF them all. the nrefly has par
ticularly received attention. So
also have the sea creatures. espe-
cially she'll fish. For years. one
might say for a century or so. sci
entists have concentrated upon the
lirht-flashing insect. No one could
seem to discover how the FREELY did
n. although many experiments were
made and many books written
about it.
1t is now generally held that
Prof, Raphael Dubois, of the Uni
versity of Lyons, France, finally
discovered what happens in the
body of the insect and the sea fish
when light appears.
All forms of animal phosphores-
cence were traced by Prof. Dubois
TO the COmDlnatlOn OF TWO principles
which he named respectively luci-
fereine and luciferase. These two
active principles are serreted sep
arately by the animal. Individually
they show no light. but when these
oils" are combined and oXygenated
by muscular action. a phosphores-
cent glow is at once produced. Prof.
Dubois also speaks of blood rush
ing into the gland tissues and caus-
ing the light to glow brightly.
1t seems that luciferine is the ac-
tual light-producing substance.
while luciferase is a natural oxid-
isinC agent by which the forme~ ie
excited. Luciferase. however, can
he replaced by certain artificial OK
idisers. such as hydrogen. peroxide,
which also cause the light to glow,
Function in Egg.
Prof. Dubois declares the light
making function. in insects al
ready appears in the egg.
1T is" he says. the ancestral
torch. which passes. without beinc
extinguished for single instant,
from the egg to the larva, to the
nymph. to the perfect insect and
from this to the egg once more;