The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1897-03-05

suggested in the net that all voluntary
effort. however slight, is associated
with increased strain upon the organs
OF respiration and the viscera generally,
as is shown in psychological laborator-
les in all experiments of innovation
and inhibition of movement You will
md that purely mechanical causes do
SO much in altering the lines along
which the growth and evolution of or
ganic forms proceed, that it is only
necessary to take into account a very
minute preponderance of weight or
force in the putting forth of muscular
effort as a cause for the preferential
activity of one side of the body. An
exceedingly slight displacement of the
center of gravity from the median line.
which begins after the second month of
foetal life, ought TO be sufficient to pro-
duce a number of concomitant vari-
atoms in the anatomy and functions of
the visceral organs, and especially in
the right lung, hardly noticeable, but
still just enough to account for the de-
Election of the main current of intelli-
gent, difficult, specialized muscular
activity TO the hand and arm of one
side rather than the other.
A concomitant is not necessarily a
cause, but it is more likely that the
cause of right is to be
found in variations in the viscera than
in the brain. After the second month
OF foetal life the apex of the embryonic
heart is crowded to the left by the
liver. The right lung has three lobes,
the left only two. Professor Baldwin.
of Princeton, in Mental Development"
reports that in his experiments his
child used either hand TO grasp a
coveted object when so close that no
exertion was needed in reaching for
it, but as soon as it was removed sew
eral inches and muscular effort ac-
cOmpanied by ra pid breathing followed,
then the right hand only was ex-
tended. You notice it was not until
the more iaborious exertion brought
the lungs into play, and the one-sided-
ness of the viscera became operative,
that the child showed any preference
for either hand.
With this visceral-mechanical cause
in view you can also account for the
asymmetry of the two sides of the
brain. The one-sidedness of the Wis
cera, slight as it is, may be sufficient
to cause Sc to 9S per cent of mankind
to be right handed, and their being
makes them left-brained
the pyramidal decussation of
the nerves connecting the right side
of the body with the left half of the
BRAIN The chief difference between
the cerebral hemispheres lies in the
fact that the developed centers for
speech and writing are located on the
side of the brain opposite to and, there
fore, connected with the preferred side
of the body. There are portions in the
motor areas of both sides of the brain
capable of being developed into two
centers for speech and two centerS
for writing, although only one of each
kind is fully developed in the whole !
brain. Aphasia, the loss of speech, |
when it occurs in a right-handed man, |
is associated with paralysis of the
right side of the body and disease of |
the left side of the brain. The same |
is true of agraphia, the loss of writ |
ing. A sufferer from aphasia or /
may gradually recover the /
lost power through the development |
Of new speech or writing center in /
the unused and undeveloped area
adapted to such work in the opposite |
half of the brain. The conditions are
in the case of a left-handed |
man, except when he is trained TO use
The right hand in penmanship. In that
case, while his speech center has been
developed on the right side of his
brain, his writing center is developed
On the left.
SHOULD CHILDREN BE TAUGHT
TO USE BOTH HANDS?
Teachers are confronted by the ques-
ion as to whether children should be
.aught to use both hands equally we'll
n writing, drawing and other skilled
Because idiots use both