Evening star., 1935-12-24

The earth wears bullet-proof shirt.
1t is a loose-fitting garment of ozone.
the gas which results when three atoms
of oxygen unite to form molecule quite
different in its properties from the
atmospheric oxygen molecule Whlcn
consists of two atoms.
Such a gas, distinguished by its pun
gent smell, is formed by an electrical dis
charge through air and can be detected
after lightning stroke. 1t is supposed
to be invigorating. This ozone shirt is
a complete protection against the par
ticles of ultraviolet light which per-
petuaIly are raining on the planet from
the sun. Thus considerable range Of
the ultra violet section Of the solar
spectrum is shut of from the earths
surface.
This light has powerful bio-chemical
effects. If any considerable amount OF
it got through it is difficult to say what
might happen, but it is almost certain
that life on earth could not continue in
its present form. The ozone layer in
the atmosphere is formed by the pas
sage of the light photons themselves.
The results of recent researches on the
"ozone shirt" were revealed before the
Chemical Society of Washington the
other night by Dr. Oliver Wulf of the
Fixed Nitrogen Laboratory of the De-
partment of Agriculture, whose own re-
searches have gone far to clear up pre-
vious misconceptions. They have estab-
lished the fact that this atmospheric
layer, of such extreme Importance to
living things, really almost hugs the
earth. 1t is only about 20 miles in alti-
tude, whereas previously it had been
supposed that it was so or 10 miles high,
constituting sort of planetary overcoat.
DR.. Wulf's conclusions, reached from
theoretical considerations. that the ozone
layer came just above the level Of the
highest stratosphere flights has been sup
poorted, he said. by photographs taken
automatically from pilot ballons recently
sent 80 miles above the earth's surface.
These showed that the great bulk of the
ozone lay below this altitude.
The location of the ozone layer was the
most practical achievement reported by
DR.. Wulf in the recent study of the chem
ical composition of the layers Of the
upper atmosphere. 1t has been as yet
impossible, he said. to determine whether
the earth'S supply of free hydrogen is
escaping lIlJO OuCeT space. II IIllS can
be determined it will have far-reaching
implications The question hinges, he
said, on whether the upper reaches Of
the atmosphere are hot or cold. 1t is
known that temperature decreases
rapidly with altitude up to great heights
so miles or more. But above that con-
siderable amounts of incoming solar
radiation are absorbed by the gas par
ticles-largely single oxygen and nitrogen
atoms which are not constituted into
molecules. This process naturally would
heat them.
1t is possible. he reported to the Wash
ington chemists, that this heat is rapidly
reradiated into outer space-in which
case the outer limits of the earths atmos-
phere are extremely cold. From the
nature of the atmospheric atoms, how
ever it is difficult to understand how they
are able to radiate, or get rid of their
accumulated heat in any other way.
If it is hot at the edge of the atmos-
phere the extremely light hydrogen par
ticle reaching there would have such
speed of propulsion outward that 1t soon
would be free of the gravitational attrac-
ton of the planet. If it is cold 1t Will
be held back in the earth's atmosphere,
possibly to combine with oxygen and
form molecules Of water.
Another moot question, DR.. Wulf said.
Is whether there are any free hydrogen