Milford chronicle., 1903-01-30
RADIUM, THE NEW LIGHT.
Il Is the Rarest and COstIiest Sub
stnnce In the World.

stance In the World.
Radium is the name Of a marvellous
new mineral with which Professor George
B. Pegram Of Columbia university is
experimenting. It's existence in the uni
verse was not suspected until recently.
Here are few amazing facts about it:
An ounce of radium is worth $2J0,00O
1t is the rarest substance in the world.
Only a few grains Of free radium are in
existence.
Its light will bore through solid metal
plates and will make a photograph after
passing through a sheet of tin.
Fifty tons of pitch blcnde treated chem
ically for three months would yield few
grams Of radium.
Radium will give out light for an in
definite time without heat and with the
expenditure of no energy whatever.
From a tiny quiet bit of white radium
salt particles of matter are constantly
shot of with the inconceivable velocity Of
light. These particles have the quality
of light. Rarer still, they possess the
property of rendering other substances
capable Of giving off light.
So iufnitesimal are the amounts Of this
substance yet massed that few expert
menters have ever actually seen a particle
OF radium Nearly all work is carried on
with radium salt, which is in effect the
metal uranium mixed with radium.
Radium light is simply light-it heats
nothing, it moves nothing.
A plate six inches square covered with
radium would shine on indefinitely. At
the end of 5000 years it would have pro-
duced heat enough 10 raise the tempera-
ture Of one gram Of water one degree cen
tigrade
Should enough radium ever be separat-
ed from its compounds it would reyolu-
tionize the lighting Of the universe. New
York city's lighting system. once installed
with raGum lights, could be run forever
at the cost OF the original plant.
Radium is found in pitch blende and
gold ores. Down in the deepest mine,
whore a ray of sunshine has not pene-
trated for 10,O00,C00 years, bit Of ra-
dium continues TO give oft its strange
light It may be prepared in the dark
and kept in The dark, and its radio actiy-
ity viii continue.
No other substance in the world shines
by its own light. PhoSphorescent bodies .
store Up sunshine and then give it off .
gradually in minute quantities. The sup .
ply is soon exhausted if the phosphores-
cent body is shut away from the suns
rays. The frebug comes nearer to being
an independent light plant. 1t derives
its phosphorescent properties from its
food This, however, in the last analysis
is derived from sunlight.
The various apparatus employed in the
Columbia university laboratory in expert
ments with radium are among the most
delicate instruments in scientific use.
H., q es...- 4.
ing to a statement by Professor Hallock
to reporter. is the one with which Pro-
fessor Pcgram has measured the energy
of the light given off by radium. 1t is
similar to the radiometer 1t measures
heat to an amount which is iniinitesimal-
Is small to the human mind. Ii candle
were placed four feet il front of a con
cave mirror two feet in diameter and al
lowed to shine on it for twelve seconds.
l-OS, 10000 of the heat generated would
defect the measuring apparatus 1-4,O90
of a foot
Radium will measure the heat of a
candle IG,CO0 miles away. Professor
Nichols has measured the heat of several
stars with it.
The instrument consists Of two small
disks Of mica suspended by spun glass
threads from the two ends of glass
beam. The glass beam is adjusted to
move on a pivot Both disks of mica are
covered with lampblack One is protect
ed from light; the other is exposed. The
whole apparatus is inclosed in a vacuum.
Inside the vacuum is placed a little bit Of
'adium salt.
The radium gives out its light, and the
heat which it generates causes an expan-
sion Of the air in front of the exposed
iiak. A vacuum. of course. holds the
smallest imaginable amount of air. Ra-
iium produces an infnitesimal amount
If heat. Yet so nicely does the machine
work that its detection can be measured.
nus giving the amount of heat in radium
light.
Only one firm Of chemists in New York
ity manufactures radium They usually
,eep four or five little vials of the salt on
land. The walls are about one inch long.
IS big rs a lead pencil, and each is about
ne-siXth filed The radium salt in these
ottles is worth s. Il gram 1t is white
nd family luminous.
Hold particle Of the salt before the
yes and an impression of light is receiv-
d. Yet if piece Of the salt the size Of
pea were hidden behind Il plate of iron
World cloud photograph plate on the
ther side
The New York firm obtains its radium
rom the ''tailings' OF western gold ore
Jew York World