The star. (Reynoldsville, Pa.) 1892-1946, 1893-04-12
NAMING liz LIQUID D AIR.
A SCIENTIST EXPLAINS HIS CHEM
icAL DISCOVERIES.


Tho Pail Mall BUDGET Of London pub
lishcd an interview with Professor ia jos
Dewar on what is represented rs being
"a great scientific discovery" that Of
maxine liquid air Introductory to the
interview the article says that "nif liq-
uefactinns of permanent glsn8 8ul ,.'
use of wanna 10 preserve great cold mark
one Of the most important chemical dis
coycrics of the century lt j. hell by
scientists that amy gas may hJ liluaiiol
if the pressure and cold may BE- uh,uiucd
and vessel of sihiciont strength to
withstand the great pr 5suros.
Oi the gases that may be liquefed car
bonic acid gas has been found to be he
cheapest and rcaliast made and while it
has been known for many years that 1t
could be liquified il has generally been
so prepared only in small quantities for
scientific uses. The use of compressed
airasa motive power has presented many
difficulties, the principal one being its
bulkiness; hence large vessels must be
used in order to get sufficient amount
of motive power, and it is hard to make
light in weight.
As a motive power 1t is used at u pres
sure of from 600 to 900 pounds. But if
Professor Dewar has discovered an eco
nomical and ready way of liquefying 1t,
it will tend to solve problem in carry
ing motive power in storage bulk that
will be of great benefit To the students in
this line. In the talk with the represent
ativo of The Pail Mall Budget he says:
well, | don't think there's very much
TO say, because I've told all have to tell
about the matter in my two lectures.
but do believe there's Il great deal moro
to hr learned about the subject. You
see, ~ presnut we've got these gases down
to 2lO degrees below zero, and the lowest
possible temperature is 2il degrees be-
low. If we could get some 30 degrees
lower down, we might liquefy hydrogen.
Hydrogen has never been liquefied in
free state yet
Now. its Il strange thing that air can
be made into homogeneous fluid. You
would think. rs oxygen can be liquetied
at -1s2 degrees and nitrogen not until
-102 degrees. that as You made the air
colder and colder the oxygen woul be-
come liquid first and then the nitrogen.
saw that prediction made in stand
ard work only the other day. Now, I
dare say, You will ask why the oxygen
don't come down first"
Stepping quickly back to the desk Pro-
fessor Dewar took up pencil and be gan
10 draw with rapid strokes on the back
Of letter The diagram when it was
finished looked more like the law of d.
minishing returns turned up ON one side
than anything else that am acquainted
with. While he drew he rapidly ex-
planned how the influence of atmospheric
pressure on the different volumes of nj
trogen and oxygen in air makes them
boil almost exactly at the same tempera-
ture. AS he made each point he frowned
little, drawing up the wrinkles between
his eyes. "Now, that, in the old theo-
logical days, would have been taken as
aprovidential dispensation. The strange
thing is that when liquid air evaporates
again they are under the same pressure,
and the nitrogen goes off first, as you
would expect.
''Ozone can be liquefied by acting on
the vapor given off from liquid oxygen
by electricity. 1t is splendid dark blue
color almost ms dark as indigo. Ozone
has not the same molecule as oxygen,
and the electricity breaks up three twos
into two threes. That is the secret of it,
The queer thing about liquid ozone is
that when it goes back into gas again it
explodes. You wouldn't think it, but it
is stronger than dynamite as an explo-
sive. It's simply because the ozone goes
back into the molecular form of oxygen
so fast. The force that comes from the
electricity makes it explode without
meeting with any outside body. It's n
tremendous explosive.
I'VE have discovered that liquid oxy-
gen acts us lens. 1t is so transparent
to heat, so to speak, that even at 1872
degrees below zero you can focus heat
Oh it from one side and light piece of
paper by it on the other. You know
that's just what happens in the earth.
The suns heat gets focused on to the
earth through the lens formed by the
vacuum of space, which is so cold that it
hasn't any temperature ut all-absolute-
ly zero"
Professor Dewar gave a lecture on
"Liquid Air" at the Royal institution in
the presence of the Prince of Wales, the
Duke Of York, Lord Salisbury AMI other
notable persons. He showed that by the
withdrawal of heat the air is converted
into IA liquid with total loss of chemical
properties, incapable of supporting COM
bustion, or of entering into combination
even with phosphorus and sodium, while
certain physical properties remain. The
conversion of oxygen into ozone was also
described, and the retention by oxygen
Of its peculiar optical properties at the
lowest temperature was demonstrated
by the very dense and well defined bands
Of its spectrum. In ordinary conditions
oxygen shows no unreasonable thermal
absorption, but at low temperature its
thermal absorptive power becomes mani
fest.
YhwQrtinC an Enemy,