Evening star., 1952-04-11
Strange World Opened
In Study of U|trosonics
Apparatus Producing Waves
Held Invaluable to Science
By Thomos R. Henry

HeId Inv0luoDIe to Science
By Thomos R. Henry
A strange world is being opened to
science through the gate of ultraSonics.
Some of the results have just been re-
ported to the Office of Naval Research
here by Drs. Ernest Yeager and Frank
Hovorka of the Navy-Sponsored Ultra
sonics Research Laboratory of Western
Reserve University.
There, they report, apparatus has
been constructed capable of producing
waves with a frequency of 100000
vibrations a second, approximately 40
times the highest sound which the
human ear can hear. The intensity
of these ultrasonic waves. related to the
loudness of ordinary sound, is more than
a million times the intensity OF the
sound waves next to the motors of an
airplane at take-off. The molecules of
any liquid exposed to such waves are
shaken so violently that they expert
ence an acceleration of 10000 miles per
second, or more than a million times
the acceleration of gravity at the earth's
surface.
These waves are proving valuable
tools for chemistry. If intense ultra
sonic waves. for example, are sent
through liquid in which gases have
been dissolved a large number of bub-
bles are formed in the path of the
waves. AS each bubble forms it rises to
the surface and the gas escapes into
the surrounding atmosphere. Thus ul-
trasonic waves can be used to degas
liquids.
Energy Converted to Heat.
When such waves are absorbed within
u system the energy associated with
the wave motion Is converted into heat.
The system may become hot enough to
decompose or burn. For example, the
eXperimenterS report, If a small bit of
plastic Is placed in liquid in the path
of intense ultrasonic waves the plastic
will absorb them quickly and may heat
up to temperature at which it burns
or explodes, although the liquid remains
at room temperature.
If intense ultrasonic waves are
passed into water containing dissolved
oxygen gas, hydrogen-peroxide is pro-
duced. If they are introduced into wa
ter containing dissolved nitrogen, am
monia may result.
At the Western Reserve laboratory
ultrasonic waves have been used to
dsperse in water everything from cook
Ing fats to aluminium. This is due to
the fact that the sound radiation can
break any solid or liquid into particles
small enough to stay suspended In wa.
ter despite the force of gravity.
A prenatal sex-determination test
which depends on some as yet unidenti-
ned substance in the saliva of the ex-
pectant mother has just been reported
to the American Association for the
Advancement of Science here.
For some time experiments have been
carried out with a pregnancy test, said
to be effective within two weeks after
conception, which depends on the pres
ence of certain steroids in the urine.
This led Drs. G. w. Rapp and Garwood
c. Richardson Of Loyola University, Chi
cago. to look for this substance in other
body fluids, such as sweat saliva and
tears.
Delivery Backed Up Tests.
They found. they report, "that in only
some OF the women who were in the
sixth or seventh month of pregnancy
did the test prove positive when the
saliva was tested In each of these
cases, however. the test was positive
on the urine. The apparent answer to
the problem was forthcoming only
after the delivery of the child. In
nearly every case the positive tests were
associated with male child and most
OF the negative tests were associated
with female child.
''The precise nature of the substance
responsible for the positive test is not
known. 1t is believed that some andre.
genie (male hormone) substance is be-
ing identified. A non-pregnant female
normally yields negative test but after
the Injection of testosterone or andro-
sterone strongly positive reaction re-
suits. Male saliva and blood serum are
all strongly positive reactors.
"The selective excretlon of certain
blood constituents through the salivary
gland is we'll known. These findings il
lustrate rather delicate selectivity OF
female salivary glands in their capacity
to screen out certain female ssociated
hormones but to allow certain male
associated ones to pass into the salivary
fluid"