Evening star., 1935-11-09

An explosion with a force of $4,000
horsepower inside the body
Such a type of wound is possible with
bullets travelling at a speed of $500 feet
per second and something approaching
the World War.
This has been demonstrated by Army
officers experimenting with the effects of
high h-speed projectiles at the Aberdeen
Proving Grounds. Pigs, goats, balls Of
clay and cans filled with water have
been the victims of bullets fired at speeds
of from approximately 100 to $500 feet
a second.
Army doctors, treating the injured at
field hospitals and dressing stations on
the Western Front sometimes encoun-
tered wounds of type new to their ex-
perience. Tissues were found injured for
long distances from the path of the
bullet or fragment of Shrapnel which
had entered the body. The zone of
injury seemed to extend in radiating
lines from the path of the projectile.
Fatality was more likely to be due to
this radiating destruction than to the
actual penetration of some vital organ
by the missile.
The explanation of these wounds IS
provided by the Aberdeen experiments,
according to report by Lieut.. Col.
George r. Calender and Sergt r. w.
French which has just been published
in the Military Surgeon. organ of the
Army Medical Corps. Injuries OF the
same type may be expected on future
battleflelds.
When a bullet strikes flesh or bone 1t
is slowed up. This means that there
has been an absorption Of energy. The
lost energy does not disappear into thin
air. 1t Is expended in the medium
through which the bullet is passing
causing radiating lines of injury in all
directions and chiefly along the paths OF
least resistance. The amount OF energy
increases in proportion to the speed with
which the bullet strikes the body and
with the density of the resisting material
whether bone or flesh.
Still another factor may complicate
the situation. The force of the impact
sets up energy waves moving through
the body and some of these may have
velocities in excess of the velocity OF
sound waves. Bio-chemiSts have shown
that waves of such frequency will coagu-
late albumin. This coagulating effect
may be one reason for the radiating tissue
injuries.
The Army doctors and ordnance ON
GERS made exact determinations OF the
energy expended by bullet in passing
through the body of one of their expert
mental animals. The speed of the pro-
5ectile before striking and after 1t left
the body was measured by an automatic
device. From the loss Of speed 1t was
possible to calculate the energy left be-
hind. Then the actual injuries caused
by this expenditure of energy were
checked. They found, as was to have
been expected both from theory and
from the World War experience, that at
initial velocities of from 1000 up to
2,700 feet per second blood vessels were
ruptured at considerable distances from
the path Of the bullet and that there
was severe destruction with relatively
small wounds.
Almost Invariably the greater the loss
In velocity the more severe the wound.
Col. Calender thus sums up the con-
clusions:
The forces Of bullets entering duid-
filled viscera are transmitted equally In
all directions, following the laws OF
hydraulics This accounts for the ex-
plosive ruptures
The physical disturbances in medium
traversed by bullet, while initiated by