Evening star., 1938-06-23
OF STARS,
MEN AND ATOMS
Notebook of Science Pro&ress
in the Laboratory and
Field.
Bv Thomas r. Henry.

surgical probes through the skin OF
Mother Earth to depths OF 20 miles or
more in research program to be car
ried out this summer under the auspices
of the Geological Society OF America.
The study will be directed by DR..
Louis B. Slichter Of the Massachusetts,
Institute of Technology, with groups Of
geologists stationed in New England
stone quarries at varying distances apart.
DR.. Slichter hopes to shed light on the
hypothesis that the earths crust is COM
posed of a number of rock layers like an
onion.
The earth is pictured by most geolo-
giSts as consisting Of series of concen-
trio shells-an outer layer of sedimen-
tary rock, an underlying granite shell,
shell of peridotite or basic rock and
core of nickel or iron, with a transi-
tional layer between the peridotite and
the core.
Twelve supersensitive seismographs
will be placed at regular intervals within
100 miles or more Of the blast to record
the results of the man-made earth
quakes. The workers hope to get infor-
nation on the nature of the rocks by
the time elapsing between the explosion
and the recording Of the shock at the
field stations. Earthquake waves travel
more swiftly in rocks of increasing
depths. DR.. Slichter expects that his
research this summer will determine
accurately how swift are wave velocities
in the deeper cuStal rocks.
Cosmic rays which penetrate so feet
into the earth are heavy eectrons. it
has been demonstrated by experiments
,ct n%o H,yH
and Volney c. Wilson of the University
Of Chicago.
This newly discovered particle has the
same size as an electron but mass of
from 100 to 200 times that much. 1t has
been named the "baryton."
y ~
With the mad dog season here again,
the Department of Agriculture issues
some timely observations on the symp-
toms Of rabies
mouth, DR.. H. w. Schoening of the
Bureau OF Animal Husbandry points out
In fact, he seldom does. The really sus-
plicable change in the disposition of the
animal. When a naturally cross dog
becomes affectionate and naturally
be in the initial stages OF the dreaded
disease. This is followed in a few DAYS
by an irresistible tendency to roam. The
dog fights or bites anything that inter-
feres with its freedom.
There is another type of rabies. how
ever, in which the animal Is depressed
from the beginning and hides The first
symptom commonly noted is paralysis of
the lower jaw. The dog acts as if it had
bone in its throat The paralysis
progresses until the victim dies
Bureau of Animal HuSbandry experi-
ments, DR.. Schoening says indicate that
resistance to rabies can be increased in
many dogs by single injection of rabies
vaccine. This resistance, however, is
only relative. 1t may be strong in some
animals and weak or lacking in others
The vaccine, however. is entirely safe
and cannot actually cause case of the
disease. 1t contains no living virus and
is manufactured under Federal auspices.
X
method Of measuring differences in
thickness Of less than a hundred mil
llonth OF an inch is reported by DR..
Katharine Blodgett OF the General Elec-
trio Company.
The color Of very thin films, such as
the reddish or blush films of oil that
cover summer street puddle, varies
directly with the thickness, she found,
A reddish oil film, for example, is ap-
proxlmately nine-millionths of an inch
thick. A straw-yellow color indicates
thickness OF seven -millionths of an inch,
A Shift from one color to the next in the
spectrum involves change in thickness
OF from one to two millionths of an inch.
IhlS has been recognized for some
time, but hitherto it has been difficult to
measure the thickness Of films because
ordinarily they are changing color rap
ioly. 10 solve this problem DR.. Blodgett
used films made of barium stearate, q
KIND OF soap. 1t can be prepared in lay
ers OF known thickness. BY piling such
layers on top Of each other and observ-
ing the color changes she was able to
establish color scale. Thus the thick
ness OF film can be instantly deter
mined by noting its color. The eye easily
can detect differences in thickness of as
little as ten-millionth of an inch and
With suitable optical apparatus differ
ences of hundred -millionth easily can
be determined
Lessons in the brain may be diagnosed
by involuntary movements of the eve
recorded by a new ticker-tape device
constructed by DR.. Ward c. Halstead of
the University of Chicago.
The eye. DR.. Halstead explained acts
like miniature storage battery with
about millionth Of the strength of a
battery used in an automobile. Every
time the eye moves there is a fiuctuation
OF current detectable by electrodes placed
over the lids and attached to a specially
constructed amplifier.
Inc device is expected to be of use in
recording the eye movements of patients
with aphasia, or loss of language, and in
stuoles OF hallucinations, fantasy and
imagination.