INSUFFICIENT SLEEP.
We learn the most important lessons from observing the facts and studying
the operations of nature, and it is largely by such a course that we may
hope to learn the true method of either understanding or practising such
courses in life as will conduce to health.
From the time of birth until the body finally rests in its last sleep, the
human system requires periods of repose under the conditions of sleep. The
child, during the first few months of its existence, passes the larger
portion of the time in this state. While in it, the brain and nervous
system develop more rapidly, grow in stability, and attain capacity for
activity more surely than is possible in any other.
It is true that we do not yet understand precisely in what the phenomenon
of sleep consists; we do not know fully what change in the operation of
the brain occurs for its induction. It may be from deviated or lessened
currents of blood in certain portions, or from the opposite condition.
Both these theories have been advocated by men more or less eminent as
physiologists; some maintaining that while in sleep the brain contains a
larger amount of blood, that there exists a diminished action of the
vaso-motor nerves which control the coats of the vessels of the brain, and
that in consequence they become more fully distended than when the brain
is in a conscious state of activity.
On the other hand, others become equally positive, from observations made
on portions of the brain which have become exposed through the effects of
injuries to the skull, that these vessels contain less blood during sleep
than when in other conditions. I think these observations are conclusive,
and that there can be no doubt as to the fact that there exists a
diminished quantity of blood in the vessels of the brain in sleep; but
that this is the cause of the occurrence of that condition of the brain
which constitutes sleep does not appear to be so certain. It is quite
possible that this diminished quantity of blood is rather a _consequence_
than a _cause_. I am more inclined to think that sleep is primarily caused
by a diminution, or cessation, of some of the electrical currents which
constantly are passing through portions of the brain while in a state of
consciousness, and which are probably necessary to a condition of
consciousness, and that the anaemic condition of the brain which is
observed during sleep is a result of such change in these currents.
But from whatever primary cause it may occur, we know that it is only when
there are frequent periods for this condition of the brain in the case of
the child, that its nervous system develops and becomes strong in the
largest measure. And on the other hand, when, for any cause, whether it be
pain or artificial excitement, sleep is prevented, the whole system
speedily becomes deranged, and manifests its sense of indignation by
irregular or imperfect development and suffering.
The necessity of sleep for the system might be illustrated by the
presentation of many remarkable and curious facts, such as those of
persons who are greatly exhausted sleeping during surgical operations; of
physicians sleeping while walking to or from visits to their patients, or
while sitting beside them when in conditions of great suffering. I have
myself, when greatly fatigued from excessive professional labor, slept
through a considerable portion of a disagreeable and somewhat painful
dental operation. The torture resulting from the deprivation of sleep for
long periods is said to be greater than that of hunger or thirst, or from
the infliction of the severest bodily injury.
Accounts received from persons who have been shipwrecked, or exposed in
open boats upon the water in situations of great personal danger, and
where, in consequence, no sleep could be indulged, go to confirm this
view; and, though these accounts may have been somewhat exaggerated, and
reporters have drawn somewhat upon their imagination in their efforts to
depict these experiences, yet those who have been long deprived of sleep,
and have been obliged to struggle against its mastery day after day, may
easily imagine how terrible must be the suffering under such
circumstances. And yet, how little this imperative demand of nature and
the importance of this great necessity of the brain have been understood,
especially in reference to children.
When a young man and a student, I well remember hearing some lectures from
a person calling himself a physician, in which he took the ground that
fifteen minutes was ample time in which to take a regular meal, and that
all time spent in sleep in excess of four or five hours at most, was so
much lost time; that if persons slept only five hours instead of eight,
they would gain more than six years of time in the course of fifty;
therefore, every person who was so much of a sluggard as to sleep eight
hours instead of five, was responsible for wasting six years in fifty.
That ambitious insect, the ant, was held up by the doctor as an example of
industry and lofty enterprise, worthy the imitation of everybody who
expects to do much in life--as if he knew how many hours that creature is
in the habit of sleeping every year.
He might almost as well have put his case stronger, and argued that it was
everybody's duty to sleep only two of the twenty-four hours, because,
forsooth, we would gain more than twelve years in the fifty by so doing.
Unfortunately for society, this man has not been alone in advocating such
views. There have been others who, in their teachings, have greatly
underestimated the importance of an abundance of sleep as a means of
securing and maintaining a high standard of health. I think that most
persons, especially of the laboring classes, in cities as also in the
country, sleep too little. This is true as to adult persons, but to a much
larger extent of children, and it is hardly possible to over-estimate the
good effects arising from an abundance of sleep upon the brain of the
child.
There are certain physiological and anatomical conditions existing which
tend to show why this is true.
1. The brain at an early age attains a size out of proportion to other
organs and members of the body. This is especially true of that portion of
the brain supposed to be concerned in mental operations, while those
portions whose office is connected with the organic life of the system are
less advanced. After twelve or fourteen years of age, the relative
rapidity of development as to size becomes changed, and other portions of
the system increase more rapidly.
2. The cells of the hemispheres of the brain contain a considerably larger
amount of water during the younger periods of life than they do during the
adult period. One of the results of this condition of the brain is that of
less stability of character, and a larger measure of susceptibility. It is
more sensitive and easily disturbed by external surroundings, while the
influences which act upon it, in connection with its daily experiences,
tend to create a much more rapid metamorphosis of its tissues.
The nerve tissue of the brain in adult life is the most unstable in its
elemental composition of that of any organ, but in childhood and youth the
change resulting in degeneration and restoration of tissue is much more
rapid than at any other period. Hence the importance of frequent and
considerably long-continued periods of sleep and inactivity of this organ.
Now, my observation and experience lead me to believe that young children
in our cities sleep far too little to enable the brain to receive the
largest benefit from it; that they are out on the streets, or employed at
tasks, long after they should have been in bed. In many portions of our
large cities there exist excitement and noise, which are quite sufficient
to prevent sleep, until the system is very greatly fatigued, and the
nervous elements exhausted. Parents are frequently thoughtless and
careless in this respect, and the children are left out on the street or
visiting at neighbors' houses until too late an hour.
A teacher in a public school informs me that one of the greatest
hindrances in the advancement of some of her scholars, lies in the fact
that one or two nights of every week these children are out at musical or
dancing parties, or attending some place of public amusement, so that the
period of sleep is greatly abridged, and the brain has not recuperated its
energy so as to be able to study. The sensitive tissue is in a condition
of too great weakness to be much used, and in consequence the difficulty
of learning lessons is greatly increased.
Again, children are often called in the morning, long before enough sleep
has been secured to refresh the brain, and employed in different ways,
perhaps in attending to some piece of machinery in a large factory, which
is filled with dust and the noise of thousands of wheels, and kept there
ten or twelve hours a day; and the brain is not allowed to sleep for
sixteen or seventeen hours.
Now, one of the effects of these long periods of wakefulness and
over-activity is to check the normal development of the brain, to stint
its growth, and give it a twist from which it never recovers. This habit,
formed in childhood, frequently extends into adult life, and becomes so
fixed that it is difficult for the brain afterward to change its custom.
The period of wakefulness tends to increase so that sleep is limited to
six or seven instead of eight or nine hours.
That man who regularly and soundly sleeps his eight or nine hours a day
should be the man capable of large physical or mental work; moreover, he
is the man who lasts longest; his system becomes daily recuperated, and he
has the largest prospect of reaching his threescore and ten, while yet his
system is in a degree of health; while his neighbor, less favored in this
respect, becomes old at sixty if he chances to live so long.
It is not intended to imply that there may not be exceptions to this rule.
There have been some who could do with four or five hours' sleep for many
years and do good work, and there are probably such men to-day, but they
are using up the nervous energy and strength with which they have been
endowed far too rapidly; and they are exceptions to the mass of people,
who require much more sleep in order to enjoy good mental health.
Sleep is to the brain what rest is to the body:
"Sleep, that knits up the ravelled sleeve of care,
The death of each day's life, sore labor's bath,
Balm of hurt minds, great Nature's second course,
Chief nourisher in life's feast."
No words could paint more beautifully or effectively the office of sleep,
than these of England's greatest poet. But we need not turn to the writers
of prose or poetry in the past for instruction in this matter; all nature
teaches the importance of sleep. Every tree, and shrub, and vine, has its
period of sleep, and, if stimulated into ceaseless activity, would soon
die; and every portion of the human system is subject to the same great
law of necessity.
The stomach must have its periods of inactivity and rest; and there are
periods during every twenty-four hours when the kidneys secrete very
little, if any, urine. It is sometimes said the heart is an exception to
this rule; that its beat never ceases from more than six months before
birth until nature's last great debt is paid in death. But, in truth, it
is at entire rest nearly if not quite one third of the whole time. Its
action consists of a _first_ and a _second_ sound, covering the
contraction of right and left auricles and ventricles, and then a
rest,--and so far as we know a perfect one. Reckoning this at one third
the time occupied in each full action of the heart, and we have more than
twenty years of perfect quiet out of the threescore and ten.
The same is true to even a larger extent of other involuntary processes
and movements; for instance, that of respiration. The muscles concerned in
this operation are at entire rest during more than one third of the time,
and if the process of respiration be much quickened in frequency for any
considerable period of time, weariness and languor ensue.
Now the brain is no exception to this same law. During every moment of
consciousness this is in ceaseless activity. The peculiar process of
cerebration, whatever that may consist in, is taking place; thought after
thought comes forth, with no volition on our part; long trains of
meditation come forth unbidden, one after another, from the hidden
recesses of the brain; sometimes things supposed to be long since
forgotten, which have for years been consigned to the rubbish lumber-heap
of dead plans and disappointed expectations, rise up suddenly, like a
frightened bird before the hunter. Then, again, the sound of some voice,
or the strain of some music long unheard, or the glance of an eye, will
call up the memories of some bitter and suffering experience with its ten
thousand harrowing associations, which go marching forward and backward
through the trackless channels of the brain like a vast army of ghosts.
All this when the brain has no set task to perform, no intent purpose to
follow out, and the body is at ease; and it is only when the peculiar
connection or chain of connection of one brain-cell with another is
broken, and consciousness fades away into the dreamless land of perfect
sleep, that the brain is at rest. In this state it recuperates its
exhausted energy and power, and stores them up for future need.
The period of wakefulness is one of constant wear; every thought is
generated at the expense of brain-cells, which can be fully re-energized
only by periods of properly regulated repose. It not unfrequently happens,
however, that sleep is only partial; that the brain still continues in
some degree of activity, and when we wake, we have dim memories of
sub-conscious thought, which has been moving through the brain. Such rest,
for the brain, is imperfect, and we are conscious of the conditions of
fatigue, which shows how imperative is the necessity for sound, healthy
sleep; and if this is not secured, if the brain, through over-stimulation
and thought, is not left to recuperate, its energy becomes rapidly
exhausted; debility, disease, and finally, loss of power supervene.
Hence the story is almost always the same in the history of the insane;
for weeks or months before the active indications of insanity appear, the
patient has been more than usually anxious about some subject or other,
and worried and wakeful, not sleeping more than four or five hours out of
the twenty four. The trains of thought have been left too long moving on
in certain channels of the brain, some experience has made too profound an
impression, and the effects of what we call the will have been unable to
control it; or there has been perhaps some source of eccentric irritation
which has been reflected; or it may be that the blood, upon which every
organ depends for nourishment and strength, has been poisoned, or its
nutrient properties impaired; and the poor brain, unable to do its
constant work under such influences, begins to waver, to show signs of
weakness or aberration; hallucinations or delusions hover around like
floating shadows in the air until, finally, disease comes and
"Plants his siege
Against the mind, the which he pricks and wounds
With many legions of strange fantasies,
Which, in their throng and press to that last hold,
Confound themselves."