The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1901-08-11
ABSOLUTELY ZERO POINT,
Prof. Dewar Reaches Temperature
That Freezes Hydrogen

mat Hfee2eS hydrogen.
A matter of interest in scientific cir
Gies IS the experiment recently made by
Pfof. James Dewar before the Royal So
elety Of London. the result of which was
the reduction of hydrogen to a solid. 5y
which the celebrated chemist reach Il
the lowest temperature ever attained in
laboratory. In other words, Prof. De-
war has reached a point considerably
nearer what is termed the absolute
zero than has ever been achieved bv
science. This absolute zero is to chem
ISIS what the pole is to geOgraphers and
naturalists, and While we are getting
nearer to both, the real significance Of
reaching the goal seems even now to be
purely a matter of speculation in the
case or the absolute zero" as well as
IN that of the north pole
by absolute zero is meant the lowest
temperature compatible with heat-that
point of temperature, in fact, at which
body would be wholly deprived of heat
and at which the paaticles whose motion
constitutes heat would be at rest The
temperature is supposed to be about PA
degrees centigrade, or -461 degrees Fab
renheit. The term heat is here used
In It's scientific sense, for as men use the
word IN everyday language it's signifi-
canoe depends on the temperature Of the
human body. Men call warm" every-
thing with a temperature higher than
their own, and cold all those objects
which have less heat than they. In
reality, however, the coolest body known
to man is far from being utterly with
out heat Ice, for example, has heat,
only IN degree so much below man s
temperature that one can scarcely I'M
aSlne 1t to be anything but CODA
term which actually implies a compare
lively low degree Of heat Accordingly
the zero of thermometers is only a con-
ventional point, marking csrta'n degree
OF heat. There seems to be a point, how
ever, where heat ceases absolutely, and
this point it is which is known in chem,
istry as the absolute zero"
The progress made in the direction Of
TINS absolute zero" is associated with
the work of Transforming a highly Vola-
t TIE gas IKE hydrogen into a liquid and
from LIQUID into a solid, because the
process or liquefying or solidifying gases
is practically process of lowering their
temperature. To convert gaseous hydro
gen, Tor example, into liquid we place a
nulp OF this gas in vessel containing
liquid air. Then by exhausting the air
SO as to make it evaporate we lower the
temperature Of the bulb until its con-
TENTS pass from gaseous into LIQUID
state. When we put some alcohol on the
palm OF the hand the evaporation of the
alcohol makes our hand cold This is
due to the fact that in evaDoratine the
alcohol needs heat to separate its par
tlcleS and to reduce it from a LIQUID TO
gas, and this heat is drawn from orr
hand. In like manner the evaporation
OF the liquid air in the vessel robs the
hydrogen of the bulb Of a considerable
Quantity of its heat, lowering it's temper
Azure until 1t becomes q liquid just as
Yapor assumes the form of water when
tne surrounding temperature is consId-
erably lowered.
Helium is the name of a newly discoy-
ered chemical element which is even
more volatile than hydrogen, and Prof.
DeWar says that by using hydrogen, in
IIquld or solid form, as a cooling agent
we ought to be able to liquefy this gas
IN the same manner as hydrogen is
Ilqueued by means of liquid air This
would pT1ng us to a boiling point about
Iouf or flVe degrees above absolute zero.
mus, even liquid helium (were the
production Of such a substance within
our means would not be enough to reach
the absolute zero" Another gas would
nave to be found, still more volatile than
hellum, in order that the IiuuefViner Of
that gas, with liquid helium for cooling
agent, might bring us to the desideraturn
of scientific chemists
This subject was discussed RECENTLY IN
an interview by DR.. Robert Huebner y
well known chemist and bacterioIogist.
II the whole world We're, al absolute zero
the whole world would be dead " he said
Life and all the forces and manifesta-
lions OF life mean motion. Can YOU i'm
aslne existence without motion? But.
then, why give so much latitude 10
ones imagination? Frof. Dewar is M
dreamer. He is a scientist, and he likes
TO nave hard ground to tread upon
Inc nearer we get to the absolute zero
the more We know of the nature Of
things. There is no telling what sort of
chemical combinations, impossible now.