Evening star., 1948-10-20
Stars, Men and Atoms -
Pocket-Sized Detector
Of Rodiooctivity Sought
Device Being Developed for Navy,
TB Becoming Mans Disease
By Thomas r. Henry

By Thomas X. Henry
A pocket-sized radioactivity detector-in
which small diamond may be an important
elements being developed by scientists work.
ing under an ONCE Of Naval Research con.
tract.
Something Of the sort might well be essen
tial equipment for millions in an atom-bomb
war
The best instrument developed to date Is
the Geiger counter. 1t records electric pulses
set up when a gamma ray, an alpha particle,
an electron or neutron knocks planetary
electron from, an atom in a gas-filled chamber.
In spite Of recent improvements, the counter
Is cumbersome and heavy to carry about.
The substitute under consideration is Q
crystal counter" crystal Of some type is
used which ordinarily Is complete electrical
nonconductor When such crystal is struck
by a radioactive particle some Of the electrons
In its atoms are so disarranged that for an
instant an electric current will flow through it.
Some Worthless for Purpose. ~
The principle is the same as that Of the
Geiger counter, but in a solid particle will
pass through about thousandfold more atoms
in the same length Of path than in a gas.
Theoretically, the crystal counter might be a
thousand times smaller than the gas-chamber
counter and just as efficient.
Some diamonds appear to provide excellent
crystals for the purpose. Others are WORTH
less. The reason for the difference is not clear.
Several types of synthetic crystals show the
same properties. None of them unfortunately.
is cheap The physicists were disappointed to
nnd that table salt was no good
once Of Naval Research scientists empha-
size that the work still is in its preliminary
stages and that a perfected crystal detector
stiA may be q long way in the future.
AA
tuberculosis Is becoming mans disease.
The white plaques death rate in the United
States now is nearly twice as great for men as
for women.
This curious trend is shown in tuberculosis
statistics for the past 81 years Just compiled by
the United States Public Health Service.
During this period the death rate for the
country as q whole has declined enormously
from approximately $50 to little more than IS
per year for each 100000 Of the population.
With education and sanitation the disease long
since has lost its place as the countrys greatest
killer. Nearly every year has shown decline.
But there has been an overwhelming gap be-
tween the death rates for males and for fe.
males
More Than so Per Cent Difference.
At the start of the period about fifth more
men than women died of the malady. Now
there is difference of more than 30 per cent
between white men and white women. Among
the colored population the difference is not so
marked, but still "a per cent more males than
females died.
The statistics show curious age differences in
tuberculosis death rates between the sexes
Among white males the rate rises steadily from
about 2 per 100000 for boys between 10 and IL
to . maximum Of about 103 between the ages
Of 65 and IA. White females show a sharp rise
in adolescence and the early 2os. But the mum.
Der Of deaths levels OF between % and IS and
then shows slight decline until the age of IS.
Then there Is a gradual increase up to the 18th
year. At no time above the age of 80 does the
rate for women equal the rate for men. Among
colored people there are the same general diff.
ferences, although less pronounced
No effort is made to explain the curious diff
ference uncovered.