The Columbia herald. [volume] (Columbia, Tenn.) 1850-1873, 1872-05-03

While the functions Of the tissues
are In full activity, says Professor
Humphrey, +. II. s., slight deteriora-
ton of structure takes place, which,
affecting the voluntary systeu-the
muscles and the hemispheres Of the
brain-causes the sense of firing, and
necessitates q period of rest for the
restoration of the tissues to its former
condition.
In the case of the muscles, this rest
is provided for by periods, quickly
alternating periods of action and cessa-
ton of action. But in the case of the
brain. the actions upon which con-
sclousness, volitiOn, etc., depend, can
not be thus freely suspended. Their
continuance is needed for the safety of
the body during long periods, through
the whole day, for instance; and
longer periods are therefore required
for repair. These are the periods of
sleep.
| OF the nervous system, 1t is the upper
region of the brain which ministers
to consciousness and volition, the in
tellectual operations, etc. And the
| functions of these regions not only
can be long suspended without inter-
| fering with the action of the lower
parts of the brain, which are more i'm
mediately necessary to life, but they
| are very easily suspended-slight causes,
such as jar or a shock, or an altera-
| ton in the blood current, being suffi-
| eient to stop the action of these parts
| and deprive the person of conscious
ness.
The spontaneous stoppage of their
action, consequent on the slight deteri-
Grafton of their structure from the con-
tinuance of their functions during the
day, is the. proximate cause of sleep
during the night; and the periodic re-
currence of sleep is in accordance with
the periodicity observed in several of
the nutritive functions, and indeed
witnessed in many of the other opera
tiOns of nature.
Dreams, Mr.. Humphrey does not re-
gard, as has been supposed by some, to
be necessary attendant on, or feature
of, sleep, but rather to be the result of
an abnormal condition. In the natural
state, We should pass from wakefulness
to complete Inconsistencies, and vics
Ter sa, quickly, almost instantaneously;
and many persons habitGally do so.
But the transition period is sometimes
prolonged, and stages are observable.
The first thing that occurs in the
lowering or cessation of that control
over the mental processes which is the
highest of our powers, the one reQuir-
ing the greatest effort and the most
easily lost. In this condition, the
thoughts ramble unchecked, chase one
another confusedly over the mental
field, and give rise TO all sorts of incon-
gruities of the imagination.
AT the same time, being unrestrained,
they are excited, and evince efforts of
memory, and even of combination,
which, in the regular state of wakeful-
ness, they are quite incapable of.
In this way the images of persons
and places, of events and items of
knowledge, long forgotten In the ordin-
ary state, and recalled with distinct
ness, and we faucy that new informa-
ton has been acquired when it is only
forgotten facts that are recalled.
Some psychologists conceive that
dreaming depends upon the inequality
in the condition of different parts of the
brain, some being excited or wakeful
while Others are quieseent or asleep;
from this DIR. Humphrey dissents. He
rather takes the view that all parts Of
the cerebral hemispheres combine in
each of the efforts of control, con-
sciousness, memory, and other mental
acts, that all suffer alike from these
effects, alike need the restoring changes
which take place in sleep, and together
paIi pdSstt, pass through the stages OH
the way to and from sleep, in which
dreaming, sleep-walking, etc., occur.