New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1894-02-18
cCJENCE AND MECHANICS.
.,p REDUCED TO A SOLID BY COLD.
.,r oF PROFESSOR DEwARs RECENT EN-
so"N ACKNOWLEDGEMENTS IN THE PROP
rPTIES OF MATTER.

ERTIEs OF MATTER.
oor ago Professor James Dewar. of Lon
Inverted air and its constituent gases. oxy-
oO' nd nitrogen. into liquids by means OF intense
Ia The temperatures necessary were ~
eo'u ha,ov zero. c. for nitrogen; 1872 below for
o es and about eco below for air. Soon after
oN Though 4; did not attract much attention
wa" oc,uallv CONCEALED air. In some public lee
.". .as GIVEN In London. few weeks ago. he again
duced solid air. at a temperature OF 20 below
- Z, or SAG below. Fair. This time the
-. created a public sensation. and the nom
.o,er,hc press IS now making the matter generaiy
-, although Professor Dewar has. in the mean
~ ao,s little hut improve his apparatus so as to
-" ,,s OUTPUT He has not produced any more
intense cold than before
ca small was the quantity or solid air maue on
.,s recent occasion that II could not DE passeu
orrd for inspection conveniently. The demonstra-
o., ~ what he had done made TO the audience
-. means OF a ray of light thrown by lantern
.srough the freezing tube upon screen, ana
ho, was shown 20 be liquid at one time AFTER
.rd appeared in such a condition that II would not
move when shaken.
These low temperatures. toward when the
CHEMISTS have been striving for years. are to be
,oearded only to limited extent as ends. ana
more as means 10 ends. TO be sure. 1t would be
-sa, thing 20 reach 27S below zero C. Ga9 Fahr),
q this is the absolute zero below which 1t has
heen supposed impossible to go. And IL was mac
c,-atelv reported last summer that Frenchman.
plctet had actually reached that goal. But the
important practical phase Of all this business Is
the change wrought in the properties of matter
~ such temperatures Among the new points
brought out this winter by Professor Dewar are
tina, at $50 degrees below zero. c. COZ below
Fabr) metals gain in tensile strength steel be-
coming almost twice strong as AT ordinary
temperatures colors are somewhat modified and
rubber becomes more extensbie An electrical dis
whiC through
vacuu,n with a beautiful luminosity was literally
frozen out and driven back when the vacuum tube
vas reduced TO a very low temperature Professor
Dewar verified the idea of Faraday and showed
that a magnet at - 200 c. had its power Increased
20 per cent. This shown by direct experiment
nv coiling a wire around magnet and immerslng
the end Of the magnet in liquid air, when an cleo
trio current was instantly generated in the wire
The means employed in producing TINS coio' IL VII"
he remembered, is the evaporation OF highly Voaue
substances II. in room where the air mas Il
temperature of 20 degrees Fair. pours
few drops of water the muslin covering or
wet bu.b" thermometer. the mercury Will raj!
ten or twelve degrees. possibly more. the result
depending the atmospheric humidity But H.
Instead Of water. alcohol is used. its greater evap-
orative power will lower the reading about twenty
five degrees. and good sulphuric ether about nifty
Thus one with proper appliances, freeze water
IN a warm parlor. But there are much more volatile
substances than these. namely gases which have
been reduced 70 liquids under enormous mechanicai
pressure and then liberated. Sulphurous mot sui
phuric) acid may be used TO freeze mercury
chloride of methyle gives 20 or more below zero,
c.: carbonic acid. 100 below; and bsulphide or
carbon and nitrous acid, 40 below, c.. or 22o be-
low FAIR To liquefy oxygen. Professor Dewar
employed three steps: First he put the gas
under great pressure. about 100 pounds 10 the
souare inch: this enabled him to secure the result
at AS below. instead Of 1872 below. Then he lib
Grated nitrous oxide gas which had been under a
pressure OF LOO pounds. by which process he was
able 10 produce a temperature Of minus 90 c.
around small chamber. into which he introduced
ehyene under pressure Of 100 When me
inner receptacle was full evaporation was resorted
TO- and facilitated by vacuum; This gave minus
iS degrees Oxygen being thus liQuefed and under
pressure, II was employed in the same way as
thyene. freed from pressure and evaporated IN
A vacuum and then the extreme temperatures
already referred TO We're secured. There is enor-
nous waste in handling these liquids. For every
pint Of oxygen in that form applied to use Pro
lessor Dewar loses nine This fact and the mech
ansm for COMPRISING the gases make the work
enormously expensive.