Evening star., 1934-11-25
SCIENCE BOMBING
HORDES0 Of GERMS
Bacteria-KiI|ing Effects Of
Intensive Radiation
Given Study.
BY THOMAS r. HENRY.

New light Is being thrown on the
dark battlefields of the infinitely lit
tle-where countless hordes Of in
visible creatures are showered with
thick rains of invisible bullets fired
with almost the speed OF light-by
studies under way at the Bureau OF
Standards. .....
The foe consists Of billions OF tiny
organisms-visible under high
powered microscope-belonging to the
bacillus family. which is responsible
for so many human diseases. The
body surface Of one Of these germs Is
approximately a billionth Of square
centimeter. Upon the hordes Is d.
rected concentrated artillery f1re from
x-ray and cathode ray tubes, constant
streams of infinitesimal particles
fred with almost speed Of light mov-
ing through space.
Measure Area Of Rays.
yet in spite Of the intensive bonn
, bardment the hostile hordes some
times do not seem to suffer . high
death rate, although all Of them must
get in the way of some of the high
speed bullets. Bureau Of Standards
scientists tried to get at the reason
by measuring the area Of the rays
themselves and comparing them with
the area to be hit.
They found 1t to vary from .000,-
00O, ,000, ,06S Of q square centimeter for
the high-speed cathode rays to q
range Of from 000, 900 .000,072 to
about three times that amount for
the range Of X-rays generally used;
that is, the projectile had less than a
thousandth part of the surface area
J of the target, although both were un-
imaginably small.
In the world of the enthusiastically
little the bacillus is giant and is
| probably as little concerned with the
| so much timer particles striking him
as would be an elephant at a bonn
bardment of bird shot. The COMPARE
| son is vague, however, because the
shots" pass right through the bacillus
1 In a continuous column, but unless
] they hit in exactly the right place
the little organism probably Is not
greatly bothered by them.
Must Hit Heart"
| A column of the tiny bullets must
"hit the heart" or what corresponds
| to the heart, of a bacillus to kill 1t.
| Otherwise the hit is probably not fatal
and bacilli have q great tenacity OF
| life So the problem Of killing on
| malevolent organisms with radiation
! commandments would appear to be
that OF making the barrage 50 heavy
| that, by the laws of chance, somes
bullet has got to hit fatal spot Of
| each bug" This in turn raises new
problems.
The dimensional work done at the
Bureau of Standards, in which the
path of x-rays through liquids is
studied, give mathematically stated
| explanation for some Of the biological
experiments on the bacteria killing
effects of intensive radiation.
y *'**
Studies now are under way at the
bureau on one of the rarest and most
!, curious of all the 81 elements-galliun.
The strange properties Of this metallic
| element have recently promised to
make it of considerable value in in
| dustry as an alloying element in the
| cadmium vapor arc lamp, but 1t has
seldom been obtained In pure form In
SUFFICIENT quantity to determine accu-
rately its properties. It was first dis
| zinc blends.
Dificult to Freeze.
Gallium Is one Of the metallic ele-
ments, yet 1t does not freeze" or
| change from a liquid to a solid, until
the temperature Is below IS Fahrenheit
or approximately SO degrees above
the freezing point OF water. It Is the
only metal, besides mercury, which
can exist as liquid at room tempera-
lures.
Another curious property is that,
| like water, it expands rather than
contracts upon freezing. Two other
metals, bismuth and antimony, have
the same property. but their freezing"
! takes place at much higher tempera-
1 lures
Gallium, it has been determined,
also has the curious property of under
cooling; that is, the liquid metal can
be placed in temperature consider
ably below its established freezing
i point without becoming solid.
The Bureau OF Standards workers
have prepared a considerable quantity
Of gallium at least 99999 per cent
pure in order to determine its actual
properties unaffected by impurities of
! other elements which usually are
found in specimens.