Year: 1878

The common phrase Gas quick as
thought" is found to be by no means so
applicable as is generally supposed, es


pecially when it is discovered that
thought, or nervous impulse, as COM
pared with light or electricity, appears
as veritable laggard. For whilst light
travels at the rate of many thousands of
miles-about one hundred and eighty
six thousand miles, according to the lat
est researches-in a second of time,
nerve-force in man passes along his
nerves at a rate varying from
one hundred and ten or one hundred
and twenty or two hundred feet per
second. Or, to use Mr.. Cations words,
nerve force is 'far from instantaneous"
in its action, and has ''indeed no higher
velocity than that of a railway express
train" AS we could naturally suppose
from consideration of this fact, small
animals presenting us with a limited
distance for nerve-force to travel, will
avoid rapid blows and shift for them
selves in the struggle for existence at a
much quicker rate than large animals.
Take two extreme cases in illustration
of this fact. A mouse hears a suspici-
GUS or threatening sound, and at once,
SO to speak, accommodates its actions
and movements to its protection. The
ear of the mouse, as one of its
"gateways of knowledge" is situated so
close to the brain that the interval
which elapses between the reception of
the sound by the ear, or between its
transmission as an impulse to the brain
| aO6 tho Ic0T1n of command or. oaoan1
impulse from the brain to the muscles
of the body for the purpose of move
ment, is too short to be perfectly appre-
ciated by the observer. In whale, on
the contrary, which may attain length
of eighty feet, much longer interval
will elapse before action of body follows
on nervous impulse, seeing that the
nerve-impulse has longer distance to
travel. Assuming that in such animals
as the whale the nerve-action travels at
the rate of seventy or eighty feet per
second, it follows that in large whale
which has been struck near the tail by a
harpoon, a second or so will elapse be-
fore the impulse is transmitted to the
brain, whilst another second will pass
before the second impulse is sent from
the brain to put the muscles of the tail
in action for the purpose of retaliating
upon the harpooner, In such case it
lis assumed that the brain of the animal
will be the nervous center or station at
which information is received, and from
which instructions are in turn telegraph
ed to the various organs and parts of the
body. In the actual details of the case,


however, it is probable that the spinal
marrow of the animal or some part of it
would act as the shead-office" for re-
ceiving and issuing commands. We
| know that a haadlnsa frno will wine off
with one foot drop of vinegar that has
been placed on the other, and in the alb
sence of the brain we thus assume that
the spinal cord may act as a nerve
| center. Doubtless the spinal marrow


discharges this function naturally; and
in view Of this latter supposition, the in.
terval between the reception of blow
and the muscular actions of an animal
would be of less duration than in the
case we have just supposed, where the
brain is regarded as the central station
OF the nervous system. AS an eminent
authority in physical science has re-
marked, "the interval required for the
kindling of consciousness would proba-
bly, more than suffice for the destruction
of the brain by lightning, or even by q
rifle bullet. Before the organ (that is,
the brain) can arrange itself, it may
therefore be destroyed, and in such a
case we may safely conclude that death
| is painless. ha7nbers'S Journal.