The St. Louis Republic., 1903-12-31
QUEER LIGHT SEEN
IN DARKENED ROOM.
Professor E. Rutherford of Can
ada Demonstrates Power of
Radio-Activity.
BIG AUDIENCE ApPLAuDs.
Flashes Which Travel 10000
Miles a Second, Penetrate Iron
and May Cure Diseases
Are Witnessed.


topic of interest to the public and the
scientists at yesterdays session Of the
American Association for the Advance
ment OF Science. The announcement tina,
Professor L Rutherford of McGin Uni.
versity, Montreal, would give a public
lecture, illustrated with experiments, at
tracted a large number Of persons tc
the Central High School early in the aft
ernoon.
All of the various sections had finished
their sessions in time to allow the men,
bers to attend the lecture, and long be-
fore the time for the lecture to begin the
auditorium was crowded by those curious
to learn of radium and radio activity.
Professor Rutherford is a young man
but he demonstrated to his audience that
he was thoroughly informed on the sub
feet of his lecture. He spoke rapidly, SC
that at times it was hard TO follow him
through a maze of scientific technical-
ties, but he had little difficulty in keeping
his hearers interested throughout the dis
course.
While the experiments were in progress
the auditorium was darkened. SO that
the audience could the better see the faint
glow that radium gives out. Eyes were
strained in the effort to see the rays
that were invisible at first because of the
change from lightness to darkness but
when the audience, after much peering,
discovered the faint glow, Professor
Rutherford was rewarded by hearty ap-
plause.
Carroll D. Wright. the United States
Labor Commissioner and president OF
Rutherford, first requesting that the wom-
en- remove their hats.
Mr.. Wright said that the association
represents something more than scien-
tific work in the United States, that it is
American in the broadest sense, and
therefore he warmly welcomed Professor
Rutherford, who, although a resident OF
another country, is regarded as a fellow
scientist. Professor Rutherford is q
Fellow of the Royal Society. and although
young has spent the last five years in
studying radio-activity.
wOMAN'S PART IN WORK.
Professor Rutherford spoke in part as
follows:
THE subject of radio-activity is of in
terest TO the public, on account or the
interest to scientific men because of the
light which 1t throws on the important
question of the constitution of matter. ]
win give you a brief historical summary
Of radium and radio-activity.
"It was first discovered in Paris by NJ.
Honore Becqueral, who investigated the
Photographic effects of ernanations from
uranium compounds. He suspected a con-
nection between the phosphorescence pro-
duced on the walls of an X-ray tube and
these uranium rays.
''Poincare suggested that the same re-
suits would be given by bodies naturally
phosphorescent. and II was Becqueral who
found this to be true in the case OF
uranium The difference between the
uranium rays and the X-rays is that the
former are produced spontaneously and
last definitely, while the latter require a
great deal of energy to produce them.
The uranium rays have a property
which forms the basis of physical meas.
urements, namely. that of discharging an
electrified body"
Professor Rutherford demonstrated this
by means OF gold-leaf electroscope. The
leaves of the electroscope. which had
been electrified previously. were dis
charged by bringing into their neighbor'
hood very small quantity of radium
whose properties are similar to those OF
uranium. but much more intense. The
illustration was demonstration of the
tremendous power of radium. Continuing
Professor Rutherford said:
a Mime. Cure investigated to determine
khetherv other substances would act like
Uranium, and she found that thoriun
acted similarly. Later. she found that
pitch blende, an ore. found most largely ir
Austria. possessed these properties in q
Very high degree; much greater, In fact
than would be possessed either by pure
uranium or thorium. She attributed this
Increased activity to a new substance
which she called radium. She found that
the radiated power varied directly with the
amount OF radiuri present. and not at al
upon the degree of concentration OF the
substance containing it.
TEN-MILLIoNTH OF TON.
THE preparation Of radiura from the
pitch blende is a very tedious chemical
process. From one ton of the original ma
terial only about on -millionth re-
mains 1t is on this account that radiurr
derful power very i.-tie of 1t produces
very noticeable results
Since the discovery of radium two. new
Substances. called pollonium and actiniuir
waving properties similar TO radium. have
In discovered. Pure radium has radta
i've power between one and two million
tsiaes that OF pure uranium.
THE radfations from radfun are moi
ordinarily visible. feeble glow Is the
sign OF purity. The radiations may be de
tected by the horeseence produ.ei,ed ,.i,s,t bs
an ore or zinc" This was illustrated by
experiments conducted IN the darkeneo
auditorium.
'Radium produces three kinds Of % rays
erford. which are called the alpha, beta
and gamma rays, The alpha rays are
deviated in one direction, the beta rays
their neiehborhood. The gamma rays are
not devfable. The beta rays are very
similar to the. cathode rays. produced by
an electric dis,ssrge through rarins1
sases They consist OF very small particles
Of matter negatively electrified. and NOV
ing with speed equal to half that OF
HEhtI J. ]. Thompson estimates that
the E3xe Of these particles Is one-one thou
andlh that of an atom Of hydrogen.
THE alpha rays have different properties
ard are the most important. They con-
sist OF particles OF matter about the size
cf hydrogen atom and arc positively
electrified. They move with the speed OF
Ebuuf 1000 miles a second Their pres
ence may be detected by an instrument
called the as e. sir,s IN @nen sae
coated with sufphide OF zinc. Under the
MInence OF the bombardment of particles.
escreen glitters with particles OF light
~ Professor Rutherford was unable tc
ID 5rnstrate this because he did not have
XptnthRriscope. he had to use the stere-
orzlcou as substitute The siides We're
70 arranged that the effect OF the rays
Atx1kfng the screen gave on brilliant