Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-05-13
INTENSIVE STUDY
OF CATHODE RAY
Research Is Designed to Open
Way for Use in Medical
Science.

With instruments. ir1closed in a 90
ton lead vault, the x-ray division of
the Bureau of Standards has started an
intensive study of the cathode ray, one
Of the most powerful agencies known
to science.
This study is designed especially to
open the way for the use of cathode
ray treatment in medicine, where 1t
may have great potentialities. Before
physicians can use 1t with safety on
living tissue much experimental work
must be done to determine the effect of
different doses. The basis of this must
be means of accurately measuring the
doses themselves which is the first OBJ
jective of the Bureau of Standards.
The cathode ray consists of stream
of electrons, negatively charged parti-
cles, shot from vacuum tube through
which very heavy voltage of electricity
is passed-from 100000 to 100000 volts.
This stream of particles can be pro-
jected from a few inches to several feet
beyond the window of the tube. The
passage of the electrons Is marked by a
blue 1uminescence plainly visible IN
front of the tube in the darkened vault.
This stream of billions of electrons
moves at approximately ne-tenth the
speed of light, or nearly 1000 miles a
second. Something happens to whatever
gets in its way-just what is not clearly
understood. When the electrons mt
atoms in their path, whether of the air
or any other substance, they produce
x-rays. They have little penetrating
power and are quickly absorbed when
they strike a screen Of any sort.
Operators Must Be Protected.
The power of the electrons to produce
l:1k. thar Snl1fre
makes 1t risky to stay in the neighbor-
hood of a cathode ray tube in operation
without complete protection. To pre-
vent possible injury to operators, the
vault is so arranged that the current
cannot be turned on until the door is
closed from the outside. Then the re-
sulting phenomena are watched through
lead glass window. 1t would not DE
necessary to stand in the path OF the
stream to get the effect because some
cathode rays are escaping from the
sides of the tube itself and A-rays are
moving in all directions.
When the negatively charged particles
penetrate living tissue they create *
rays within the body which naturally
heat up the cells, and would cause
severe burns. Here lies both the danger
and the possible therapeutic value. Al
though creating x-rays wherever 1t
strikes, the cathode ray itself is very
different from the X-ray, although the
instruments which produce them super
f1cially are similar. The cathode stream
is actually of moving particles while the
X-ray is an extremely short light wave
in the invisible spectrum which moves
at the speed of light and penetrates
deeply into most substances with which
1t comes in contact Thus its thera-
peutic value lies largely in its ability to
reach deep-seated conditions, such as
internal cancers. The possible thera-
peutic value of the cathode ray is in
superficial ailments, such as skin and
scalp conditions. It will kill every sort
of bacteria with which it comes in con-
tact other uses are the taking of
shadow pictures of very delicate tissues
and the effect on certain chemicals.
Seek to Measure Rays.
Another medical use in the light of
recent experiments is the treatment of
ergosterol and cholesterol, the two mys-
ferrous chemical substances which be-
come extremely rich in certain vitanins
after appropriate radiation. Physicians,
however cannot afford to use cathode
rays until they have some way of calcu-
lating the amounts with which they are
dealing. The Bureau of Standards is
interested primarily In the physical
problem of being able to measure them.
They hope, however to make some tests
with animals to determine the safe
dosage which may be directed against
human tissue.
For the first few years after Roent-
gems discovery of the X-ray, says
Lauriston s. Taylor, associate physicist
in charge Of the X-ray division, 1t was
OF no value In medicine because there