The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1903-09-13
CONCERNING TWO
NEW ELEMENTS
Nine. Curie Discourses
on Polonium and.
Radium.
Cause Of Mysterious Prop.
critics Of Radio Active
Substances.

Several bits of history new to most
readers are brought out by Nine. Curie.
One is the share which she and her
husband had respectively In the IA
nous discovery Of polonium and ra-
dunn. AS long ago as 1898 she had found
that salts of thorium emitted substan-
TALLY the same peculiar radiations as
uranium compounds A German,
Schmidt, seems to have hit upon the
( fact simultaneously but. SO far as the
Paris chemists were concerned, Mime.
Curie alone deserves the credit of that
discovery 1t was then noticed that
large number of natural minerals, which
are mixtures of several salts, but which
contained either radium or thorium,
were radioactive. At first 1t was be-
lieved that one or the other OF these two
metals was responsible for the phenom-
enon. Nine Curie then undertook an
experiment which suggested different
conclusion.
One Of these minerals was chalcolite,
which is a compound of phosphates Of
copper and uranium. In it's native state
it was about twice as powerful as ura-
MUM in emitting what are known as
/ Becquerel rays. Nine Curte manufac-
tured an artificial chalcolite putting in
the proper ingredients to insure gen
:
hibit the same radiating power as the
native salt. This has excited a sus-
picion that some other element was
present in minute quantities in the lat
ter 1t was at this point that NJ Curie
/ was tempted to join his wife in the
hunt. Two new elements were elimin-
ated. polonium, which resembles bis
muth in it's chemical properties. and ra-
dunn, which is allied TO Darium. For
the second of these part of the honor is
due to NJ. Bemont, who assisted in the
research.
What Nine. Curie says about the
cause of the mysterious properties re-
Gently observed deserves to be quoted
in full
From the beginning of the investiga-
/ lions on radioactive substances the
spontaneity of their radiation has been
a problem which has had the greatest
interest for all students and investiga-
tors in physics. To-day we are further
advanced in our knowledge Of radio
active substances, and we know how to
isolate one radioactive body of great
radiant power-radium. BY taking ad-
vantage of the wonderful properties Of
radium we have succeeded in making a
profound study of the rays emitted by
radioactive bodies generally. The diff
ferent kinds of radiations which have
been studied up to the present time all
present certain analogies with the
groups of rays which exist in Crookes
tubes. with the so-called cathode rays
and with the Rontgen rays. Similar
groups of rays are also to be found in
the secondary radiations produced by
Rontgen rays. and in the radiation from
substances which have by induction, ac-
quired radio-activity.
While the nature of the radiation is
actually better known than before, the
cause Of spontaneous radio-activity re-
mains as much of mystery as ever and
this phenomenon is still an enigma for
us spontaneously active substances,
and, above all, radium, are sources of
energy. The amount of energy in which
/ they give rise is revealed to us by the
radiations of Bacquerel and by the
chemical and luminous effects produced,
and the fact that there is a constant
disengagement of heat
1T has been asked, then, if the en-
ergy thus manifested is created in the
radioactive substances themselves or
rather, if it is not borrowed by them
from external sources. None of the nu-
merous hypothesis which have been
founded on these two methods Of view
ing the question have as yet received
any experimental confirmation"-Th
( INDEPENDENT