HYGIENE OF THE NERVOUS SYSTEM.
793. As the different organs of the system are dependent on the brain
and spinal cord for efficient functional action, and as the mind and
brain are closely associated during life, the former acting in strict
obedience to the laws which regulate the latter, it becomes an object
of primary importance in education, to discover what these laws are,
that we may escape the numerous evils consequent on their violation.
794. _For healthy and efficient action, the brain should be primarily
sound_; as this organ is subject to the same general laws as other
parts of the body. If the brain of the child is free from defects at
birth, and acquires no improper impressions in infancy, it will not
easily become diseased in after life. But, if the brain has inherited
defects, or has acquired a proneness to disease by mismanagement in
early life, it will more easily yield to influences that cause
diseased action. The hereditary tendency to disease is one of the most
powerful causes that produce nervous and mental affections.
Consequently, children have a strong tendency to the diseases from
which the parents suffered.
795. When both parents have similar defects, or have descended from
tainted families, the children are usually more deeply impressed with
their imperfections than when only one possesses the defect. This is
the reason of the frequency of nervous disease and imbecility among
the opulent, as intermarriages among near relations are more frequent
with this class than among the poor.
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793-850. _Give the hygiene of the nervous system._ 793. Why is it
important to know the laws which regulate the action of the brain?
794. What is necessary that the action of the brain be healthy and
efficient? What follows if the brain of the child has inherited
defects? 795. What is the effect when both parents possess similar
defects?
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_Observation._ Among some of the reigning families of Europe,
particularly the Spanish, the folly of intermarriage among themselves
is strongly illustrated. The high and noble talents that characterized
their progenitors are not seen, but there is now exhibited, among
their descendants, imbecility and the most revolting forms of nervous
disease.
796. "Unhappily, it is not merely as a cause of disease, that
hereditary predisposition is to be dreaded. The obstacles which it
throws in the way of permanent recovery are even more formidable, and
can never be entirely removed. Safety is to be found only in avoiding
the perpetuation of the mischief."
797. "Therefore, if two persons, each naturally of excitable and
delicate nervous temperament, choose to unite for life, they have
themselves to blame for the concentrated influence of similar
tendencies in destroying the health of their offspring, and
subjecting them to all the miseries of nervous disease, madness, or
melancholy." The command of God not to marry within certain degrees
of consanguinity, is in accordance with the organic laws of the
brain, and the wisdom of the prohibition is confirmed by observation.
_Observation._ The inhabitants, females particularly, of the sea-girt
islands of America, are more affected with nervous diseases, than
those who reside upon the mainland. The prevalence of these affections
is ascribed to the frequent intermarriage of persons closely related
by blood.
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What is one cause of nervous disease among the higher classes? What is
true of some of the reigning families of Europe? 796. Why is
hereditary predisposition to be dreaded? 797. Is the prohibition of
God respecting intermarriage in accordance with the organic laws of
the brain? What is said of the inhabitants of the sea-girt islands of
America?
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798. _The brain requires a due supply of pure blood._ This organ
receives an unusually large supply of blood, in comparison with the
rest of the body. It is estimated that one tenth of all the blood sent
from the heart goes to this organ. If the arterial blood be altogether
withdrawn, or a person breathes air that is filled with carbonic gas,
the brain ceases its proper action, and sensibility with consciousness
becomes extinct.
_Illustrations._ 1st. If a person lose a considerable quantity of
blood, dizziness and loss of consciousness follow. This results from
the brain not receiving a sufficient amount of blood to sustain its
functions.
2d. When an individual descends into a well or pit that contains
carbonic acid, the blood is not changed or purified in the lungs, and
loss of consciousness and death soon follow.
799. The slighter variations in the state of the blood have equally
sure, though less palpable effects. If its vitality is impaired by
breathing an atmosphere so much vitiated as to be insufficient to
produce the proper degree of oxygenation, the blood then affords an
imperfect stimulus to the brain. As a necessary consequence, languor
and inactivity of the mental and nervous functions ensue, and a
tendency to headache, fainting, or hysteria, makes its appearance.
_Observations._ 1st. Let a person remain, for a time, in a crowded,
ill-ventilated, hall or church, and headache or faintness is generally
produced. This is caused by the action of impure blood upon the
brain.
2d. If a school-teacher wishes to have his pupils, on the day of
examination, appear creditably, he will be careful to have the room
well ventilated. Ventilating churches might prevent the inattention
and sleepiness that are observed during the afternoon service.
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798. Why does the brain require a due supply of pure blood? What is
the effect when a person loses a considerable quantity of blood? What
causes the loss of consciousness when carbonic acid is breathed? 799.
What effects are produced by slight variations in the quality of the
blood? From the following observations, give some of the effects of
impure blood on the brain.
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3d. In many instances, the transmission of imperfectly oxygenated
blood to the brain, is an influential cause in the production of
nervous disease and delicacy of constitution. The only efficient
remedy for these conditions is a supply of pure blood to the brain.
800. _The brain should be called into action._ This organ, like the
muscles, should be used, and then allowed to rest, or cease from
vigorous thought. When the brain is properly called into action by
moderate study, it increases in size and strength; while, on the other
hand, if it is not used, the action of this organ is enfeebled,
thereby diminishing the function of all parts of the body.
801. The brain, being an organized part, is subject, so far as regards
exercise, to the same laws as the other organs of the body. If it is
doomed to inactivity, its size diminishes, its health decays, and the
mental operations and feelings, as a necessary consequence, become
dull, feeble, and slow. If it is duly exercised after regular
intervals of repose, the mind acquires readiness and strength. Lastly,
if it is overtasked, either in the force or duration of its activity,
its functions become impaired, and irritability and disease take the
place of health and vigor.
802. The consequences of inadequate exercise will first be explained.
We have seen that by disuse the muscles become emaciated, the bones
soften, and the blood-vessels are obliterated. The brain is no
exception to this general rule. It is impaired by permanent
inactivity, and becomes less fit to manifest the mental powers with
readiness and energy. Nor will this surprise any reflecting person,
who considers that the brain, as a part of the same animal system, is
nourished by the same blood and regulated by the same vital laws as
the muscles, bones, and arteries.
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800. Why should the brain be called into action? 801. What is the
effect if the brain is doomed to inactivity? 802. Show the consequences
of disuse of the organs mentioned in preceding chapters. Does the
same principle apply to the brain?
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803. It is the weakening and depressing effect which is induced by the
absence of the stimulus necessary for the healthy exercise of the
brain, that renders solitary confinement so severe a punishment, even
to the most daring minds. Keeping the above principle in view, we
shall not be surprised to find that _non-exercise_ of the brain and
nervous system, or, in other words, inactivity of intellect and
feeling, is a very frequent predisposing cause of every form of
nervous disease.
804. For demonstrative evidence of this position, we have only to look
at the numerous victims to be found among females of the middle and
higher ranks, who have no calls to exertion in gaining the means of
subsistence, and no objects of interest on which to exercise their
mental faculties, and who, consequently, sink into a state of mental
sloth and nervousness, which not only deprives them of much enjoyment,
but subjects them to suffering, both of body and mind from the
slightest causes.
805. But let the situation of such persons be changed; bring them, for
instance, from the listlessness of retirement to the business and
bustle of the city; give them a variety of imperative employments, and
so place them in society as to supply to their cerebral organs that
extent of exercise which gives health and vivacity of action, and in a
few months the change produced will be surprising. Health, animation,
and energy, will take the place of former insipidity and dulness.
806. An additional illustration, involving an important principle in
the production of many distressing forms of disease will be found in
the case of a man of mature age, and of active habits, who has devoted
his life to the toils of business, and whose hours of leisure have
been few and short. Suppose such a person to retire to the country in
search of repose, and to have no moral, religious, or philosophical
pursuits to occupy his attention and keep up the active exercise of
his brain; this organ will lose its health, and the inevitable result
will be, weariness of life, despondency, or some other variety of
nervous disease.
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803. What renders solitary confinement so severe a punishment to the
most daring minds? What is a predisposing cause of nervous disease?
804. In what classes do mental and nervous debility prevail? 805. How
can this be counteracted? 806. Give another illustration, showing how
disease of the brain is induced.
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807. One great evil attending the absence of some imperative
employment or object of interest, to exercise the mind and brain, is
the tendency which it generates to waste the mental energies on every
trifling occurrence which presents itself, and to seek relief in the
momentary excitement of any sensation, however unworthy. The best
remedy for these evils is to create occupation to interest the mind,
and give that wholesome exercise to the brain, which its constitution
requires.
808. _The evils arising from excessive or ill-timed exercise of the
brain, or any of its parts, are numerous._ When we use the eye too
long, or in too bright a light, it becomes bloodshot. The increased
action of its vessels and nerves gives rise to a sensation of fatigue
and pain, requiring us to desist. If we relieve the eye, the
irritation gradually subsides and the healthy state returns. But, if
we continue to look intently, or resume our employment before the eye
has regained its natural state by repose, the irritation at last
becomes permanent, and disease, followed by weakness of vision, or
even blindness, may ensue.
809. Phenomena precisely analogous occur, when, from intense mental
excitement, the brain is kept long in a state of excessive activity.
The only difference is, that we can always see what happens in the
eye, but rarely what takes place in the brain; occasionally, however,
cases of fracture of the skull occur, in which, part of the bone being
removed, we can see the quickened circulation in the vessels of the
brain, as easily as those of the eye.
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807. What is one great evil attending the absence of some imperative
employment to exercise the mind and brain? What is the true remedy for
these evils? 808. From what other cause do evils arise to the brain?
Explain the evil of it by the excessive use of the eye. 809. What is
the only difference in the analogy of the phenomena of the eye and
brain? Has the analogy been verified?
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810. Sir Astley Cooper had a young man brought to him, who had lost a
portion of his skull, just above the eyebrow. "On examining the head,"
says Sir Astley, "I distinctly saw that the pulsation of the brain was
regular and slow; but at this time he was agitated by some opposition
to his wishes, and directly the blood was sent with increased force to
the brain, and the pulsation became frequent and violent."
811. Indeed, in many instances, the increased circulation in the
brain, attendant on mental excitement, reveals itself when least
expected, and leaves traces after death, which are very perceptible.
When tasked beyond its strength, the eye becomes insensible to light,
and no longer conveys any impressions to the mind. In like manner, the
brain, when much exhausted, becomes incapable of thought, and
consciousness is almost lost in a feeling of utter confusion.
812. _At any time of life, excessive and continued mental exertion is
hurtful_; but in infancy and early youth, when the structure of the
brain is still immature and delicate, permanent mischief is more
easily produced by injudicious treatment than at any subsequent
period. In this respect, the analogy is as complete between the brain
and the other parts of the body, as that exemplified in the injurious
effects of premature exercise of the bones and muscles.
813. Scrofulous and rickety children are the most usual sufferers in
this way. They are generally remarkable for large heads, great
precocity of understanding, and small, delicate bodies. But in such
instances, the great size of the brain, and the acuteness of the mind,
are the results of morbid growth. Even with the best of management,
the child passes the first years of its life constantly on the brink
of active disease.
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810. Relate the case detailed by Sir Astley Cooper. 811. May the
increased functional action of the brain change its structure? 812. At
what age particularly is excessive and continued mental exertion
hurtful? 813. What is said of scrofulous and rickety children?
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814. Instead, however, of trying to repress its mental activity, the
fond parents, misled by the early promise of genius too often excite
it still further, by unceasing cultivation, and the never-failing
stimulus of praise. Finding its progress for a time equal to their
warmest wishes, they look forward with ecstasy to the day when its
talents will break forth and shed lustre on its name.
815. But in exact proportion as the picture becomes brighter to their
fancy, the probability of its being realized becomes less; for the
brain, worn out by premature exertion, either becomes diseased, or
loses its tone, leaving the mental powers imbecile and depressed for
the remainder of life. The expected prodigy is thus easily outstripped
in the social race by many whose dull outset promised him an easy
victory.
816. Taking for our guide the necessities of the constitution, it will
be obvious that the modes of treatment commonly resorted to ought to
be reversed. Instead of straining to the utmost the already irritable
powers of the precocious child, and leaving his dull competitor to
ripen at leisure, a systematic attempt ought to be made, from early
infancy, to rouse to action the languid faculties of the latter, while
no pains ought to be spared to moderate and give tone to the activity
of the former.
817. Instead of this, however, the prematurely intelligent child is
sent to school and tasked with lessons at an unusually early age,
while the healthy but more backward boy, who requires to be
stimulated, is kept at home in idleness, perhaps for two or three
years longer, merely on account of his backwardness. A double error is
here committed. The consequences to the intelligent boy are,
frequently, the permanent loss both of health and of his envied
superiority of intellect.
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814. How are such children usually managed? 815. What is the cause of
their early promise and subsequent disappointment? 816. What mode of
treatment should be adopted in educating precocious children? 817. How
should the dull or less active child be treated? What is the usual
course?
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818. In youth, too, much mischief is done by the long daily period of
attendance at school, and the continued application of the mind which
the ordinary system of education requires. The law of exercise--that
long-sustained action exhausts the vital powers of the organ--applies
as well to the brain as to the muscles. Hence the necessity of varying
the occupations of the young, and allowing frequent intervals of
exercise in the open air, instead of "enforcing the continued
confinement now so common."
_Observation._ It is no unusual occurrence, that on examination day,
the best scholars appear indifferently. This may be the result of
nervous exhaustion, produced by extra mental effort in preparing for
the final examination. It is advisable for such pupils to divert their
minds from close study for a few days previous to examination. During
this time, the student may indulge in physical recreation, social
intercourse, and a moderate amount of reading.
819. "In early and middle life, fever, an unusual degree of cerebral
disorder, is a common consequence of the excessive and continued
excitement of the brain. This unhappy result is brought on by severe
study, unremitted mental exertion, anxiety, and watching. Nervous
disease, from excessive mental labor and high mental excitement,
sometimes shows itself in another form.
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What are the consequences of the error? 818. What error prevails in
the present system of education? Why should youths be allowed frequent
intervals to exercise in the open air? Give observation. 819. What is
a frequent consequence of continued and excessive excitement of the
brain?
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820. "From the want of proper intervals of rest, the vascular
excitement of the brain has not time to subside. A restless
irritability of temper and disposition comes on, attended with
sleeplessness and anxiety, for which no external cause can be
assigned. The symptoms gradually become aggravated, the digestive
functions give way, nutrition is impaired, and a sense of wretchedness
is constantly present, which often leads to attempts at suicide."
_Observations._ 1st. Moderation in mental exertion is more necessary
in old age than in early or mature years. In youth and manhood, the
exhaustion of the brain from over-excitement may be repaired, but no
such result follows over-exertion in the decline of life. "What is
lost then, is lost forever." At that period, the brain becomes
excited, and is soon exhausted when forced to protracted and vigorous
thought. Sir Walter Scott and President Harrison afford sad examples
of premature death from overtasked brains at an advanced period of
their lives.
2d. If the mind is incessantly engaged in the contemplation of the
same object, there is danger from over-exertion of the brain at any
period of life, but more particularly in old age. The more limited the
sphere of mental action, the greater the danger of the brain being
over-exercised. Hence the frequency of nervous diseases in poets,
mathematicians, and musicians.
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820. What often manifests itself from the want of proper intervals of
rest? Why is moderation in mental action necessary in old age? What is
the effect if the mind is incessantly engaged in the contemplation of
the same object?
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