Evening journal., 1893-04-06
MAKING LIQUID AIR.
A SCIENTIST EXPLAINS HIS CHEM
lcAL DISCOVERIES.

to BE the Greatest Investigations OF the
century-PowerfuI Gases Reduced to a
fluid state.
The Pail Mall Budget Of London pub
hshed an interview with Professor James
Dewar on what is represented as being
"a great scientific discovery" that of
making liquid air Introductory TO the
interview the article says that "his liz
uefactions Of permanent gases and the
nse OF wanna TO preserve great cold mark
oneof the most important chemical die
coverics Of the century IL is held by
scientists that any gas may be liqueiied
If the pressure and cold may be obtained
and vessel Of sufficient strength to
withstand the great pressurcs
OF the gases that may be liqueiied car
bonic acid gas has been found to be the
cheapest and rcadicst made. and while 1t
has been known for many years that It
could be liquified it has generally been
SO prepared only in small quantities for
scientific uses. The use Of compressed
airas n motive power has presented many
difficulties. the principal one being its
bulkiness. hence large vessels must be
used in order 10 get a sufficient amount
Of motive power. and it is hard to make
these strong enough and at the same time
light in weight
AS a motive power it is used at pres
sure Of from GOO TO 900 pounds. But If
Professor Dewar has discovered an eco
nomical and ready way Of liquefying it,
it win tend TO solve problem in carry
ing motive power in storage bulk that
4l.,~ 80.
this line. In the talk with the represent
ative 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 "a great deal more
to be learned about the subject You
see. at present we've got these gases down
to 9lO degrees below zero, and the lowest
possible temperature is 274 degrees be-
low. If we could get some 80 degrees
lower down. we might liquefy hydrogen.
Hydrogen has never been hqueied in a
free state yet
Now. it's a strange thing that air can
be made into a homogeneous fluid You
would think. as oxygen can be liquefed
ut --lS2 degrees and nitrogen not until
--102 degrees. that as you made the air
colder and colder the oxygen would be-
come liquid FIRST and then the nitrogen
! saw that prediction made in a stand
ard work only the other day Now, /
dare say you will ask why the oxygen
don't come down first.
Stepping quickly back to the desk Pro-
fessor Dewar took mp pencil and began
to 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 ev-
planned how the influence of atmosphere
pressure on the different volumes of nj
trogen and oxygen in air makes then
boil almost exactly at the same tempera
ture. AS he made each point he frownet
little. drawing up the wrinkles between
his eyes. Now, that, in the old theo
logical days. would have been taken a
providential dispensation. The strang'
thing is that when liquid air eyaporate
again they are under the same pressure
and the nitrogen goes of first, as yol
would expect.
"Ozone can be hquefed by acting or
the vapor given of from liquid oxygei
by electricity. Ii is a splendid dark blu
color, almost as dark as indigo. Ozon
has not the same molecule as oxygen
and the electricity breaks up three two
into two threes That is the secret of il
The queer thing about liquid ozone
that when it goes back into gas again
explodes You wouldn't think It, but
is stronger than dynamite as an explC
sive It's simply because the ozono goe
back into the molecular form of oxyge
SO fast The force that comes from Oh
electricity makes it explode without
meeting with any outside body It's
tremendous explosive.
I'VE have discovered that liquid OK
gen acts as lens II is so Transporter
to heat. so 20 speak. that even nc Is
degrees below zero you can focus hei
on il from one side and light piece
paper by it on the other. You kno
that's Just what happens in the cart
The suns heat gets focused on 10 q
earth through the lens formed by q
vacuum OF space. which is 50 cold TINT
hasn't any temperature at all-absolut
iy zero"
Professor DeNdr gave iecVuIe
Liquid Air" at the Royal institution
the presence Of the Prince Of Wales, {
Duke of York. Lord Salisbury and 9th
notable persons. He showed that by {
withdrawal of heat the air is convert
into a liquid with total loss Of chemi,
properties. incapable of supporting co
bustion. or of entering into combinati
even with phosphorus and sodium, VIII
certain physical properties remain. I
conversion OF oxygen into ozone was a
described, and the retention by oxyg
Of its peculiar optical properties at
lowest temperature was demonstrai
By the very dense and well defined bar
OF its spectrum. In ordinary conditiC
oxygen shows no unreasonable thern
absorption. but at low temperature
thermal absorptive power becomes ma
fest
ThwartiDE an Enemy.