Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-11-12
Bureau of Standards Takes
Spectrum Photographs of
Rare Matter.
RADIOACTIVE METAL
is BELIEVED VALUABLE
Scientists Expect Discovery Will
Lead Also to Finding 49, Only
Other Unknown Substance.
BY THOMAS r. HENRY.

the long, WOrld-Wlde search Tor "ele-
ment 81" may be nearing its end.
At the Bureau of Stands yester-
day spectrum photographs were taken
of an allegedly radioactive aka
line substance submitted by Prof. Gus
tave A. Aartovaara of Helsingfors. Fin
land, following shortly after an an
nouncement from the physics depart
ment of Cornell University that sub
stance with most of the theoretical
properties of "87'' had been isolated.
Long, close study of the spectrum
lines shown by the photograph will be
necessary, according to DR.. William F.
Meggers, in charge of the spectre
scopic work at the bureau, before 1t
can be determined whether the mate
rial obtained by the Finnish professor
represents something hitherto undiscov-
and if the Cornell claims are validated,
there would be one of the most re-
markable cases of dual discovery in the
history Of science.
Expected to Be Valuable.
The missing "87'' is one of the last
two unknownS among the 80 primary
substances of which creation is COM
posed But the long search for it has
been far more than the hunt for a
curiosity. 1t stands next to radium in
the atomic table. There is every reason
W UGllSVe LIldI lldNc SOIlc Vi
the properties of radium, as well as
unknown properties in its own right.
First comes element Sc, radon. This
Is the gas which is emanated from
radium and which is the material now
used In all medical work with radio
active substances. It Is not generally
known that radium itself never is used
in hospitals. Instead the radium is
kept in lead container and the gas
which comes from it pumped of every
day. This Is inclosed in small tubes or
needles and inserted into the patho-
logical tissue. Then comes the missing
"87." Then, in order, come actinium,
thorium, proto-actinium and uranium,
from which radium itself is derived,
as the heavy, unstable elements throw
of portions Of their substances.
Very far-reaching results might come
from the discovery of 49," radium's
unknown sister Thus far DR.. Meg
gers says, it has defled the utmost eff
forts of physicists the world over. al
though the present search for 1t Is
comparable in intensity to that which
radium itself early in the century.
theoretically a good deal can be de-
duced concerning 1t. It will belong to
the alkaline group of elements.
It should be radio-actfve-So heavy
that it is unstable and cannot hold it
self together, but Is constantly disin-
tegrating. Most notable Of all, 1t should
have, according to physical theory. the
lowest "ionization potential Of all the
elements. This means that one of its
electrons which Is not bound in an
electron shell and has very elongated
orbit could be torn loose with less ef-
fort than would be required to tear
away an electron from any other ele-
ment. AS the number indicates, it con-
TED Of nlonfrOY1S raVniVin0 around
central mass of electrons and protons,
somewhat after the fashion that planets
revolve around the sun.
This low ionization potential, DR..
Mergers says, may be the reason why
it has never been found. 1t is so un-
stable that it may not remain itself
long enough to be discovered. Theoreti-
caliy it should be metal, but probably
exists only as a compound 1t Is close
to the top of the atomic table, which
would make 1t one of the heaviest OF
the element. All the other radioactive
elements have been discovered years
ago.
The strange properties theoretically
attributed to this one make its iSola-
ton of especial Importance, so the
search for it has gone on steadily
wherever alkalis are found. favorite
hunting place has been the Dead Sea,
within whose waters there Is great
variety Of these substances. Most OF
them have turned out to be combina-
tions of elements long known to chem
lists.
Material Is Returned.
A year ago Dr. Meggers received some
of the material from the Finnish pro-
fessor, who wrote that he had found 1t
to be radioactive and believed that 1t
contained the missing element When
the spectrum lines which would be the
final criterion, were obtained 1t was
found that the material was very
complicated mixture Of alkallnes and
rare earths, so that 1t was hopeless job
to try to sort out the hundreds of lines.
The material was returned to Finland
with the request that the chemist re-
move the rare earths and return only
the alkalis. The spectra of all these are
well known, so that any new lines which
appeared could be detected. The ma
terial photographed yesterday was the
result of this.
If "87" is found there will still be
one element missing This will have
IS outer electrcns and belongs to the
halogen group Of elements, which in
cludes iodine, chlorine and bromine.
It must be about the rarest substance
in creation. But. DIR. MeggerS says.
there is considerable likelihood that
when "87' is found "35" will be found
hEO. Ilt dikdllS anu tIlS IldIOStIlS dlt
running mates in nature. 1t is difficult
for elements of either series to exist
alone, while they At together well be-
cause Of the nature of their electron
shells. Now, says DR.. Meggers, the
properties Of these two elements as
theoretically deduced are such that
they would be natural companions A
familiar example of the partnership of
the two families Of elements is sodium
chloride, or common table salt. So
dunn is an alkali. Chlorine is a halogen
But they commonly are found together.
Theoretically, DR.. Meggers says, there
is every reason to believe that "87" is
radioactive. The substance isolated at
Cornell, as described in bulletin from
that institution, was not radioactive
leading to the prospect of a still
further search.
Discovery of "87" and "85" would
close the table of the elements as it has
been theoretically constructed, from the
simple hydrogen at the bottom with one
electron revolving around one proton to
uranium at the top with 80 outer cleo
irons moving in a complicated maze Of
orbits about an extremely complex nu-
cleus of electronS and protons.
With "87" and "85" isolated the table
of possible elemental substances would
be completely closed. The only new
place to look for them would be beyond
Jiranium-and there is no reason tc
believe that anything heavier than thi;
heaviest of all elements exists, at least
within ths SOLAR syStema -..