Iowa state bystander. [volume] (Des Moines, Iowa) 1894-1916, 1914-12-25


OBSERVATION-DISCLOSURES
lCopsrishk. IDA. By A. s. Cray)
THE RADIOACTIVE ELEMENTS.
The discovery of the X-ray by Pro.
lessor Roentgen In 1895 familiarized
the minds Of men with type Of radi-
I alton invisible to the unaided eye but
able to traverse Opaque objects and
affect q Photographic plate behind
them. It had long been known that
certain substances exposed to sun
shine afterwards glow In the dark, a
property known as phosphorescence,
and it had been discovered that the
X.ray developed these same qualities
in these substances. This led to ex-
periments to see If similar types of
rays we're not produced in other ways.
Like many other great discoveries,
the elimination of the search owed
something to luck or accident. Henri
Becquerel in Paris in 1896 CHANGED to
use a piece Of uranium and discov-
cred in compounds of that element
carnations closely allied to the X-ray
in their general nature, property we
now call radioactivity. These new
radiations in varying extent pass
through all matter quite Independent
of whether it is opaque or transparent
to light. In addition to the proper
ties possessed by light of acting on a
Photographic plate and of causing Ger.
tain substances, like the platino-
cyanides. to fuoresce, the new redia-
lions resembled the X-rays also in
'ionizing" the air and other gases,
rendering them for the time being
partial conductors of electricity. =
! The pioneer in developments on the
chemical side was Nine. Curie, who,
with her husband, isolated radium
and polonium. Other investigators
following these lines developed some
thirty individual radio elements. AS
a result of experiments, observations
and deductions, we are beginning to
suspect that there exists in every
form of matter the process of its own
decay, and this suspicion Is gradually
crystallizing into belief, a new phil.
osophy, a philosophy destined pro-
foundry to influence. the thoughts and
actions Of future generations Of men.
The emanations from radioactive
elements have been classed as alpha,
beta and gamma rays. and are dis.
tinguished BY enormous differences In
power Of penetration. The alpha
rays have been shown to be atoms
) Of 4helium carrying an. electrical
charge, and shooting out from radioac-
tive materials in the course Of their
disintegration. The alpha rays Of
radium are distinguishable in Aene-
trating power from the alpha rays Of
Uranium and from Thorium. but the
differences among alpha rays as =
classsa small and unimportant, rela.
lively compared to the enormous Diff
ferences between any alpha ray and a
beta or gamma ray.
The most penetrating alpha ray
known IL not more than twice as pene-
trating as the least penetrating alpha
ray known, but beta rays as a class
are 100 times more penetrating than
alpha rays and the gamma rays In
turn are fully 100 times more pene-
trating than the beta rays as class
Alpha rays are completely absorbed
. by thin screens of paper or a few
inches of air, while beta rays pass
through a visiting card or ordinary
tinfoil with ease. But Soddy shows
that gamma ray will penetrate one
half inch of. steel or stack of twelve
pennies, six inches of lead or one foot
of solid iron. '.t
The compound microscope became
an efficient weapon of scientific truth
about 1880, and In 1889 Schwann dem
ons.7ated that "all the higher animals
are commemorative of cells"
Every human, individual begins life
as a single cell about a hundred and
\ twentieth Of an inch in diameter and
in the brief period of forty weeks at
tains an average weight of approx
mately seven pounds. After birth
there ensues period OF growth.
Growth is not a simple augmentation
Of volume, but an alteration in form
and type. 4. /. \ E. Ill.,. d.. ..r.
For instance, If we compare the
skeleton OF . newborn child with that
OF an adult, we discover vast differ
ences between the relative proper
stions OF the different parts. The
$child's head is enormously larger than
that OF the adult in proportion to its
stature and the chest measure also
\ IS markedly greater in the child.
These facts imply the presence Of
some check, q balance wheel or
1 growth regulator. It is easy to under
stand that anything that will throw
these growth regulation factors out of
gear must produce grave results and
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