Sleep and Its Derangements
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Title: Sleep and Its Derangements
Author: William A. Hammond
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*** START OF THE PROJECT GUTENBERG EBOOK SLEEP AND ITS DERANGEMENTS ***
SLEEP AND ITS DERANGEMENTS.
SLEEP AND ITS DERANGEMENTS.
BY WILLIAM A. HAMMOND, M.D.,
PROFESSOR OF DISEASES OF THE MIND AND NERVOUS
SYSTEM, AND OF CLINICAL MEDICINE IN THE BELLEVUE
HOSPITAL MEDICAL COLLEGE, NEW YORK; VICE-PRESIDENT
OF THE ACADEMY OF THE MEDICAL SCIENCES, NATIONAL
INSTITUTE OF LETTERS, ARTS, AND SCIENCES; LATE
SURGEON-GENERAL U. S. ARMY, ETC. ETC.
PHILADELPHIA:
J. B. LIPPINCOTT & CO.
1869.
Entered, according to Act of Congress, in the year 1869, by J. B.
LIPPINCOTT & CO., In the Clerk’s Office of the District Court of the
United States for the Eastern District of Pennsylvania.
PREFACE.
The basis of this little volume is a paper on Insomnia, published in the
New York Medical Journal in May and June, 1865. This was subsequently
enlarged and published in a separate form, under the title “Wakefulness,
with an Introductory Chapter on the Physiology of Sleep.”
The very favorable reception which it met with in this country, in Great
Britain, and on the Continent, from the medical press, the profession, and
the public generally, led to the exhaustion of a large edition in a few
months.
The present issue was announced nearly two years ago, and the printing
begun. Increasing professional duties have, however, prevented me
bestowing that continuous labor upon it which was desirable, and hence the
publication has been long delayed. My apologies therefore are due, first,
to my excellent and dear friend, the senior member of the house of J. B.
Lippincott & Co., whose patience I know has been severely tried, but who
has scarcely reproached me for my neglect; and second, to that portion of
the public which has been kind enough to make repeated inquiries relative
to the appearance of this monograph, and which I trust will not be
disappointed, now that it is really published.
162 WEST 34TH ST., NEW YORK,
_July 10th, 1869_.
CONTENTS.
PAGE
CHAPTER I.
The Necessity for Sleep 9
CHAPTER II.
The Causes of Sleep 18
CHAPTER III.
The Physical Phenomena of Sleep 52
CHAPTER IV.
The State of the Mind during Sleep 62
CHAPTER V.
The Physiology of Dreams 107
CHAPTER VI.
Morbid Dreams 147
CHAPTER VII.
Somnambulism 192
CHAPTER VIII.
The Pathology of Wakefulness 222
CHAPTER IX.
The Exciting Causes of Wakefulness 240
CHAPTER X.
The Treatment of Wakefulness 278
CHAPTER XI.
Somnolence 288
CHAPTER XII.
Somnolentia, or Sleep Drunkenness 304
APPENDIX 317
SLEEP AND ITS DERANGEMENTS.
CHAPTER I.
THE NECESSITY FOR SLEEP.
The state of general repose which accompanies sleep is of especial value
to the organism in allowing the nutrition of the nervous tissue to go on
at a greater rate than its destructive metamorphosis. The same effect is,
of course, produced upon the other structures of the body; but this is not
of so much importance as regards them, for while we are awake they all
obtain a not inconsiderable amount of rest. Even those actions which are
most continuous, such as respiration and the pulsation of the heart, have
distinct periods of suspension. Thus, after the contraction and dilatation
of the auricles and ventricles of the heart, there is an interval during
which the organ is at rest. This amounts to one-fourth of the time
requisite to make one pulsation and begin another. During six hours of the
twenty-four the heart is, therefore, in a state of complete repose. If we
divide the respiratory act into three equal parts, one will be occupied
in inspiration, one in expiration, and the other by a period of
quiescence. During eight hours of the day, therefore, the muscles of
respiration and the lungs are inactive. And so with the several glands.
Each has its time for rest. And of the voluntary muscles, none, even
during our most untiring waking moments, are kept in continued action.
But for the brain there is no rest, except during sleep, and even this
condition is, as we all know, only one of comparative quietude in many
instances. So long as an individual is awake, there is not a single second
of his life during which the brain is altogether inactive; and even while
he is deprived by sleep of the power of volition, nearly every other
faculty of the mind is capable of being exercised; and several of them, as
the imagination and memory, for instance, are sometimes carried to a pitch
of exaltation not ordinarily reached by direct and voluntary efforts. If
it were not for the fact that all parts of the brain are not in action at
the same time, and that thus some slight measure of repose is afforded, it
would probably be impossible for the organ to maintain itself in a state
of integrity.
During wakefulness therefore the brain is constantly in action, though
this action may be of such a character as not always to make us conscious
of its performance. A great deal of the power of the brain is expended in
the continuance of functional operations necessary to our well-being.
During sleep these are altogether arrested or else very materially
retarded in force and frequency.
Many instances of what Dr. Carpenter very happily calls “unconscious
cerebration” will suggest themselves to the reader. We frequently find
suggestions occurring to us suddenly--suggestions which could only have
arisen as the result of a train of ideas passing through our minds, but of
which we have been unconscious. This function of the brain continues in
sleep, but not with so much force as during wakefulness. The movements of
the heart, of the inspiratory muscles, and of other organs which perform
either dynamic or secretory functions are all rendered less active by
sleep; and during this condition the nervous system generally obtains the
repose which its ceaseless activity during our periods of wakefulness so
imperatively demands. Sleep is thus necessary in order that the body, and
especially the brain and nervous system, may be renovated by the formation
of new tissue to take the place of that which by use has lost its normal
characteristics.
From what has been said it will be seen that the brain is no exception to
the law which prevails throughout the whole domain of organic nature--that
use causes decay. The following extract from another work[1] bears upon
this point, and I think tends to its elucidation.
“During life the fluids and tissues of the body are constantly undergoing
change. New matter is deposited, and the old is removed with ceaseless
activity. The body may be regarded as a complex machine, in which the law,
that force is only generated by decomposition, is fully carried out. Every
motion of the body, every pulsation of the heart, every thought which
emanates from the encephalon is accompanied by the destruction of a
certain amount of tissue. As long as food is supplied in abundance, and
the assimilative functions are not disordered, reparation proceeds as
rapidly as decay, and life is the result; but should nutrition be
arrested, by any cause, for any considerable period, new matter ceases to
be formed, and the organs, worn out, act no longer, and death ensues.
“The animal body differs from any inorganic machine in the fact that it
possesses the power of self-repair. In the steam-engine, for instance, the
fuel which serves for the production of steam, and subsequently for the
creation of force, can do nothing toward the repair of the parts which
have been worn out by use. Day by day, by constant attrition and other
causes, the engine becomes less perfect, and eventually must be put in
order by the workman. In the animal body, however, the material which
serves for the production of force is the body itself, and the substances
which are taken as food are assimilated according to their character by
those organs and parts which require them.
“The body is therefore undergoing continued change. The hair of yesterday
is not the hair of today; the muscle which extends the arm is not
identically the same muscle after as before its action; old material has
been removed and new has been deposited to an equal extent; and though the
weight and form, the chemical constitution and histological character have
been preserved, the identity has been lost.”
All this is especially true of the brain. Its substance is consumed by
every thought, by every action of the will, by every sound that is heard,
by every object that is seen, by every substance that is touched, by every
odor that is smelled, by every painful or pleasurable sensation, and so
each instant of our lives witnesses the decay of some portion of its mass
and the formation of new material to take its place. The necessity for
sleep is due to the fact that during our waking moments the formation of
the new substance does not go on as rapidly as the decay of the old. The
state of comparative repose which attends upon this condition allows the
balance to be restored, and hence the feeling of freshness and
rejuvenation we experience after a sound and healthy sleep. The more
active the mind the greater the necessity for sleep, just as with a
steamer, the greater the number of revolutions its engine makes, the more
imperative is the demand for fuel.
The power with which this necessity can act is oftentimes very great, and
not even the strongest exertion of the will is able to neutralize it. I
have frequently seen soldiers sleep on horseback during night marches,
and have often slept thus myself. Galen on one occasion walked over two
hundred yards while in a sound sleep. He would probably have gone farther
but for the fact of his striking his foot against a stone and thus
awaking.
The Abbé Richard states that once when coming from the country alone and
on foot, sleep overtook him when he was more than half a league from town.
He continued to walk, however, though soundly asleep, over an uneven and
crooked road.[2]
Even when the most stirring events are transpiring, some of the
participants may fall asleep. Sentinels on posts of great danger cannot
always resist the influence. To punish a man with death, therefore, for
yielding to an inexorable law of his being, is not the least of the
barbarous customs which are still in force in civilized armies. During the
battle of the Nile many of the boys engaged in handing ammunition fell
asleep, notwithstanding the noise and confusion of the action and the fear
of punishment. And it is said that on the retreat to Corunna whole
battalions of infantry slept while in rapid march. Even the most acute
bodily sufferings are not always sufficient to prevent sleep. I have seen
individuals who had been exposed to great fatigue, and who had while
enduring it met with accidents requiring surgical interference, sleep
through the pain caused by the knife. Damiens, who attempted the
assassination of Louis XV. of France, and who was sentenced to be torn to
pieces by four horses, was for an hour and a half before his execution
subjected to the most infamous tortures, with red-hot pincers, melted
lead, burning sulphur, boiling oil, and other diabolical contrivances, yet
he slept on the rack, and it was only by continually changing the mode of
torture, so as to give a new sensation, that he was kept awake. He
complained, just before his death, that the deprivation of sleep was the
greatest of all his torments.
Dr. Forbes Winslow[3] quotes from the _Louisville Semi-Monthly Medical
News_ the following case:
“A Chinese merchant had been convicted of murdering his wife, and was
sentenced to die by being deprived of sleep. This painful mode of death
was carried into effect under the following circumstances: The condemned
was placed in prison under the care of three of the police guard, who
relieved each other every alternate hour, and who prevented the prisoner
falling asleep night or day. He thus lived nineteen days without enjoying
any sleep. At the commencement of the eighth day his sufferings were so
intense that he implored the authorities to grant him the blessed
opportunity of being strangled, guillotined, burned to death, drowned,
garroted, shot, quartered, blown up with gunpowder, or put to death in
any conceivable way their humanity or ferocity could invent. This will
give a slight idea of the horrors of death from want of sleep.”
In infants the necessity for sleep is much greater than in adults, and
still more so than in old persons. In the former the formative processes
are much more active than those concerned in disintegration. Hence the
greater necessity for frequent periods of repose. In old persons, on the
contrary, decay predominates over construction, there is a decreased
activity of the brain, the nervous system, and of all other organs, and
thus the demand for rest and recuperation is lessened.
The necessity for sleep is not felt by all organic beings alike. The
differences observed are more due to variations in habits, modes of life,
and inherent organic dispositions, than to any inequality in the size of
the brain, although the latter has been thought by some authors to be the
cause. It has been assumed that the larger the brain the more sleep was
required. Perhaps this is true as regards the individuals of any one
species of animals, but it is not the case when species are compared with
each other. In man, for instance, persons with large heads, as a rule,
have large, well-developed brains, and consequently more cerebral action
than individuals with small brains. There is accordingly a greater waste
of cerebral substance and an increased necessity for repair.
This is not, however, always the case, as some individuals with small
brains have been remarkable for great mental activity.
All animals sleep, and even plants have their periods of comparative
repose. As Lelut says:[4]
“No one is ignorant of the nocturnal repose of plants. I say repose and
nothing else. I do not say diminution or suspension of their sensibility,
for plants have no sensibility. I say diminution of their organic
actions--a diminution which is evident and characteristic in all, more
evident and more characteristic in some. * * *
“Their interior or vital movements are lessened, the flow of the sap and
of other fluids which penetrate and rise in them is retarded. Their more
mobile parts--the leaves, the flowers--show by their falling, their
occlusion, their inclination that their organic actions are diminished,
and that a kind of repose has been initiated, which takes the place of the
lying down, which, with animals, is the condition and the result of
sleep.”
CHAPTER II.
THE CAUSES OF SLEEP.
The exciting cause of natural and periodic sleep is undoubtedly to be
found in the fact that the brain at stated times requires repose, in order
that the cerebral substance which has been decomposed by mental and
nervous action may be replaced by new material. There are other exciting
causes than this, however, for sleep is not always induced by ordinary or
natural influences acting periodically. There are many others, which
within the strict limits of health may cause such a condition of the brain
as to produce sleep.
Authors, in considering sleep, have not always drawn the proper
distinction between the exciting and the immediate cause. Thus Macario,[5]
in alluding to the alleged causes of sleep, says:
“Among physiologists some attribute it to a congestion of blood in the
brain; others to a directly opposite cause, that is, to a diminished
afflux of blood to this organ; some ascribe it to a loss of nervous
fluid, others to a flow of this fluid back to its source; others again
find the cause in the cessation of the motion of the cerebral fibers, or
rather in a partial motion in these fibers. Here I stop, for I could not,
even if I wished, mention all the theories which have prevailed relative
to this subject. I will only add that, in my opinion, the most probable
proximate and immediate cause appears to be feebleness. What seems to
prove this view is the fact that exhaustive hot baths, heat, fatigue, too
great mental application are among the means which produce sleep.”
Undoubtedly the influence mentioned by Macario, and many others which he
might have cited, lead to sleep. They do so through the medium of the
nervous system--causing a certain change to take place in the physical
condition of the brain. We constantly see instances of this transmission
of impressions and the production of palpable effects. Under the influence
of fatigue, the countenance becomes pale; through the actions of certain
emotions, blushing takes place. When we are anxious or suffering or
engaged in intense thought, the perspiration comes out in big drops on our
brows; danger makes some men tremble, grief causes tears to flow. Many
other examples will suggest themselves to the reader. It is surely,
therefore, no assumption to say that certain mental or physical influences
are capable of inducing such an alteration in the state of the brain as
necessarily to cause sleep. These influences or exciting causes I propose
to consider in detail, after having given my views relative to the
condition of the brain which immediately produces sleep.
It is well established as regards other viscera, that during a condition
of activity there is more blood in their tissues than while they are at
rest. It is strange, therefore, that, relative to the brain, the contrary
doctrine should have prevailed so long, and that even now, after the
subject has been so well elucidated by exact observation, it should be the
generally received opinion that during sleep the cerebral tissues are in a
state approaching congestion. Thus Dr. Marshall Hall,[6] while contending
for this view, also advances the theory that there is a special set of
muscles, the duty of which is, by assuming a condition of tonic
contraction, so to compress certain veins as to prevent the return of the
blood from the heart.
Dr. Carpenter[7] is of the opinion that the first cause of sleep in order
of importance is the pressure exerted by distended blood-vessels upon the
encephalon.
Sir Henry Holland[8] declares that a “degree of pressure is essential to
perfect and uniform sleep.”
Dr. Dickson[9] regards an increased determination of blood to the
cerebral mass, and its consequent congestion in the larger vessels of the
brain, as necessary to the induction of sleep.
In his very excellent work on Epilepsy, Dr. Sieveking[10] says:
“Whether or not there is actually an increase in the amount of blood in
the brain during sleep, and whether, as has been suggested, the choroid
plexuses become turgid or not, we are unable to affirm otherwise than
hypothetically; the evidence is more in favor of cerebral congestion than
of the opposite condition inducing sleep--evidence supplied by physiology
and pathology.” Dr. Sieveking does not, however, state what this evidence
is.
Barthez[11] is of the opinion that during sleep there is a general
plethora of the smaller blood-vessels of the whole body. He does not
appear to have any definite views relative to the condition of the
cerebral circulation.
Cabanis[12] declares that as soon as the necessity for sleep is
experienced, there is an increased flow of blood to the brain.
To come to more popular books than those from which we have quoted, we
find Mr. Lewes,[13] when speaking of the causes of sleep, asserting that:
“It is caused by fatigue, because one of the natural consequences of
continued action is a slight congestion; and it is the _congestion_ which
produces sleep. Of this there are many proofs.” Mr. Lewes omits to specify
these proofs.
Macnish[14] holds the view that sleep is due to a determination of blood
to the head.
That a similar opinion has prevailed from very ancient times, it would be
easy to show. I do not, however, propose to bring forward any further
citations on this point, except the following, from a curious old
black-letter book now before me, in which the views expressed, though
obscure, are perhaps as intelligible as many met with in books of our own
day:
“And the holy scripture in sundrie places doth call death by the name of
sleepe, which is meant in respect of the resurrection; for, as after
sleepe we hope to wake, so after death we hope to rise againe. But that
definition which Paulus Ægineta maketh of sleepe, in my judgment, is most
perfect where he saith: Sleepe is the rest of the pores animall,
proceeding of some profitable humour moistening the braine. For here is
shewed by what means sleepe is caused; that is, by vapours and fumes
rising from the stomache to the head, where through coldness of the braine
they being congealed, doe stop the conduites and waies of the senses, and
so procure sleepe, which thing may plainly be perceived hereby; for that
immediately after meate we are most prone to sleepe, because then the
vapours ascende most abundantly to the braine, and such things as be most
vaporous do most dispose to sleepe, as wine, milke, and such like.”[15]
The theory that sleep is due directly to pressure of blood-vessels, filled
to repletion, upon the cerebral tissues, doubtless originated in the fact
that a comatose condition may be thus induced. This fact has long been
known. Servetus, among other physiological truths, distinctly announces it
in his _Christianismi Restitutio_, when he says:
“_Et quando ventriculi ita opplentur pituita, ut arteriæ ipsæ choroidis ea
immergantur, tunc subito generatur appoplexia._”
Perhaps the theory which prevails at present, of sleep being due to the
pressure of distended blood-vessels upon the choroid plexus, is derived
from these words of Servetus.
That stupor may be produced by pressure upon the brain admits of no doubt.
It is familiarly known to physicians, surgeons, and physiologists; the two
former meet with instances due to pathological causes every day, and the
latter bring it on at will in their laboratories. But this form of coma
and sleep are by no means identical. On the contrary, the only point of
resemblance between the two consists in the fact that both are accompanied
by a loss of volition. It is true, we may often arrive at a correct idea
of a physiological process from determining the causes and phenomena of
its pathological variations, but such a course is always liable to lead to
great errors, and should be conducted with every possible precaution. In
the matter under consideration it is especially of doubtful propriety, for
the reason stated, that coma is not to be regarded as a modification of
sleep, but as a distinct morbid condition. Sir T. C. Morgan,[16] in
alluding to the fact that sleep has been ascribed to a congested state of
the brain, for the reason that in apoplectic stupor the blood-vessels of
that organ are abnormally distended, objects to the theory, on the ground
that it assimilates a dangerous malady to a natural and beneficial
process. He states (what was true at the time he wrote) that the condition
of the circulation through the brain, during sleep, is wholly unknown.
It is important to understand clearly the difference between stupor and
sleep, and it is very certain that the distinction is not always made by
physicians; yet the causes of the two conditions have almost nothing in
common, and the phenomena of each are even more distinct.
1. In the first place, stupor never occurs in the healthy individual,
while sleep is a necessity of life.
2. It is easy to awaken a person from sleep, while it is often impossible
to arouse him from stupor.
3. In sleep the mind may be active, in stupor it is as it were dead.
4. Pressure upon the brain, intense congestion of its vessels, the
circulation of poisoned blood through its substance cause stupor, but do
not induce sleep. For the production of the latter condition a diminished
supply of blood to the brain, as will be fully shown hereafter, is
necessary.
Perhaps no one agent so distinctly points out the difference between sleep
and stupor as opium and its several preparations. A small dose of this
medicine acting as a stimulant increases the activity of the cerebral
circulation, and excites a corresponding increase in the rapidity and
brilliancy of our thoughts. A larger dose lessens the amount of blood in
the brain, and induces sleep. A very large dose sometimes diminishes the
power of the whole nervous system, lessens the activity of the respiratory
function, and hence allows blood which has not been properly subjected to
the influence of the oxygen of the atmosphere to circulate through the
vessels of the brain. There is nothing in the opium itself which produces
excitement, sleep, or stupor, by any direct action upon the brain. All its
effects are due to its influence on the heart and blood-vessels, through
the medium, however, of the nervous system. This point can be made plainer
by adducing the results of some experiments which I have lately performed.
_Experiment._--I placed three dogs of about the same size under the
influence of chloroform, and removed from each a portion of the upper
surface of the skull an inch square. The dura mater was also removed, and
the brain exposed. After the effects of the chloroform had passed
off--some three hours subsequent to the operation--I administered to
number one the fourth of a grain of opium, to number two a grain, and to
number three two grains. The brain of each was at the time in a perfectly
natural condition.
At first the circulation of the blood in the brain was rendered more
active, and the respiration became more hurried. The blood-vessels, as
seen through the openings in the skulls, were fuller and redder than
before the opium was given, and the brain of each animal rose through the
hole in the cranium. Very soon, however, the uniformity which prevailed in
these respects was destroyed. In number one the vessels remained
moderately distended and florid for almost an hour, and then the brain
slowly regained its ordinary appearance. In number two the active
congestion passed off in less than half an hour, and was succeeded by a
condition of very decided shrinking, the surface of the brain having
fallen below the surface of the skull, and become pale. As these changes
supervened, the animal gradually sank into a sound sleep, from which it
could easily be awakened. In number three the surface of the brain became
dark, almost black, from the circulation of blood containing a
superabundance of carbon, and owing to diminished action of the heart and
vessels it sank below the level of the opening, showing, therefore, a
diminished amount of blood in its tissue. At the same time the number of
respirations per minute fell from 26 to 14, and they were much weaker than
before. A condition of complete stupor was also induced from which the
animal could not be aroused. It persisted for two hours. During its
continuance, sensation of all kind was abolished, and the power of motion
was altogether lost.
It might be supposed that the conditions present in numbers two and three
differed only in degree. That this was not the case is shown by the
following experiment:
_Experiment._--To the dogs two and three I administered on the following
day, as before, one and two grains of opium respectively. As soon as the
effects began to be manifested upon the condition of the brain, I opened
the trachea of each, and, inserting the nozzle of a bellows, began the
process of artificial respiration. In both dogs the congestion of the
blood-vessels of the brain disappeared. The brain became collapsed, and
the animals fell into a sound sleep, from which they were easily
awakened. If the action of the bellows was stopped and the animals were
left to their own respiratory efforts, no change ensued in number two, but
in number three the surface of the brain became dark, and stupor resulted.
In order to be perfectly assured upon the subject, I proceeded as follows
with another dog:
_Experiment._--The animal was trephined as was the others, and five grains
of opium given. At the same time the trachea was opened and the process of
artificial respiration instituted. The brain became slightly congested,
then collapsed, and sleep ensued. The sleep was sound, but the animal was
easily awakened by tickling its ear. After I had continued the process for
an hour and a quarter, I removed the nozzle of the bellows, and allowed
the animal to breathe for itself. Immediately the vessels of the brain
were filled with black blood, and the surface of the brain assumed a very
dark appearance.
The dog could no longer be aroused, and died one hour and a quarter after
the process was stopped.
I have only stated those points of the experiments cited which bear upon
the subject under consideration, reserving for another occasion others of
great interest. It is, however, shown that a small dose of opium excites
the mind, because it increases the amount of blood in the brain; that a
moderate dose causes sleep, because it lessens the amount of blood; and
that a large dose produces stupor by impeding the respiratory process,
and hence allowing blood loaded with carbon, and therefore poisonous, to
circulate through the brain.
It is also shown that the condition of the brain during stupor is very
different from that which exists during sleep. In the one case its vessels
are loaded with dark blood; in the other they are comparatively empty, and
the blood remains florid.
I think it will be sufficiently established, in the course of these
remarks, that sleep is directly caused by the circulation of a less
quantity of blood through the cerebral tissues than traverses them while
we are awake. This is the immediate cause of healthy sleep. Its exciting
cause is, as we have seen, the necessity for repair. The condition of the
brain which is favorable to sleep may also be induced by various other
causes, such as heat, cold, narcotics, anæsthetics, intoxicating liquors,
loss of blood, etc. If these agents are allowed to act excessively, or
others, such as carbonic oxide, and all those which interfere with the
oxygenation of the blood, are permitted to exert their influence, stupor
results.
The theory above enunciated, although proposed in a modified form by
Blumenbach several years since, and subsequently supported by facts
brought forward by other observers, has not been received with favor by
any considerable number of physiologists. Before, therefore, detailing my
own experience, I propose to adduce a few of the most striking proofs of
its correctness which I have been able to collect, together with the
opinions of some of those inquirers who have recently studied the subject
from this point of view.
Blumenbach[17] details the case of a young man, eighteen years of age, who
had fallen from an eminence and fractured the frontal bone, on the right
side of the coronal suture. After recovery took place a hiatus remained,
covered only by the integument. While the young man was awake this chasm
was quite superficial, but as soon as sleep ensued it became very deep.
The change was due to the fact that during sleep the brain was in a
collapsed condition. From a careful observation of this case, as well as
from a consideration of the phenomena attendant on the hibernation of
animals, Blumenbach[18] arrives at the conclusion that the proximate cause
of sleep consists in a diminished flow of oxygenated blood to the brain.
Playfair[19] thinks that sleep is due to “a diminished supply of oxygen to
the brain.”
Dendy[20] states that there was, in 1821, at Montpellier, a woman who had
lost part of her skull, and the brain and its membranes lay bare. When she
was in deep sleep the brain remained motionless beneath the crest of the
cranial bones; when she was dreaming it became somewhat elevated; and
when she was awake it was protruded through the fissure in the skull.
Among the most striking proofs of the correctness of the view that sleep
is due to diminished flow of blood to the head, are the experiments of Dr.
Alexander Fleming,[21] late Professor of Medicine, Queen’s College, Cork.
This observer states, that while preparing a lecture on the mode of
operation of narcotic medicines, he conceived the idea of trying the
effect of compressing the carotid arteries on the functions of the brain.
The first experiment was performed on himself, by a friend, with the
effect of causing immediate and deep sleep. The attempt was frequently
made, both on himself and others, and always with success. “A soft humming
in the ears is heard; a sense of tingling steals over the body, and in a
few seconds complete unconsciousness and insensibility supervene, and
continue so long as the pressure is maintained.”
Dr. Fleming adds, that whatever practical value may be attached to his
observations, they are at least important as physiological facts, and as
throwing light on the causes of sleep. It is remarkable that his
experiments have received so little notice from physiologists.
Dr. Bedford Brown,[22] of North Carolina, has recorded an interesting
case of extensive compound fracture of the cranium, in which the
opportunity was afforded him of examining the condition of the cerebral
circulation while the patient was under the influence of an anæsthetic,
preparatory to the operation of trephining being performed. A mixture of
ether and chloroform was used. Dr. Brown says:
“Whenever the anæsthetic influence began to subside, the surface of the
brain presented a florid and injected appearance. The hemorrhage
increased, and the force of the pulsation became much greater. At these
times so great was the alternate heaving and bulging of the brain, that we
were compelled to suspend operations until they were quieted by a
repetition of the remedy. Then the pulsations would diminish, the cerebral
surface recede within the opening of the skull, as if by collapse; the
appearance of the organ becoming pale and shrunken with a cessation of the
bleeding. In fact, we were convinced that diminished vascularity of the
brain was an invariable result of the impression of chloroform or ether.
The changes above alluded to recurred sufficiently often, during the
progress of the operation, in connection with the anæsthetic treatment, to
satisfy us that there could be no mistake as to the cause and effect.”
It will be shown, in the course of the present memoir, that Dr. Brown’s
conclusions, though in the main correct, are erroneous so far as they
relate to the effect of chloroform upon the cerebral circulation; nor
does it appear that he employed this agent unmixed with ether, in the case
which he has recorded so well. He has, probably, based his remarks on this
point upon the phenomena observed when the compound of ether and
chloroform was used--the action of pure chloroform, as regards its effect
upon the quantity of blood circulating through the brain, being the
reverse of that which he claims for it.
But the most philosophical and most carefully digested memoir upon the
proximate cause of sleep, which has yet been published, is that of Mr.
Durham.[23] Although my own experiments in the same direction, and which
will be hereafter detailed, were of prior date, I cheerfully yield all the
honor which may attach to the determination of the question under
consideration to this gentleman, who has not only worked it out
independently, but has anticipated me several years in the publication,
besides carrying his researches to a much further point than my own
extended.
With the view of ascertaining by ocular examination the vascular condition
of the brain during sleep, Durham placed a dog under the influence of
chloroform, and removed with a trephine a portion of bone as large as a
shilling from the parietal region; the dura mater was also cut away.
During the continuance of the anæsthetic influence, the large veins of
the surface of the pia mater were distended, and the smaller vessels were
full of dark-colored blood. The longer the administration of the
chloroform was continued, the greater was the congestion. As the effects
of this agent passed off, the animal sank into a natural sleep, and then
the condition of the brain was very materially changed. Its surface became
pale and sank down below the level of the bone; the veins ceased to be
distended, and many which had been full of dark blood could no longer be
distinguished. When the animal was roused, the surface of the brain became
suffused with a red blush, and it ascended into the opening through the
skull. As the mental excitement increased, the brain became more and more
turgid with blood, and innumerable vessels sprang into sight. The
circulation was also increased in rapidity. After being fed, the animal
fell asleep, and the brain again became contracted and pale. In all these
observations the contrast between the two conditions was exceedingly well
marked.
To obviate any possible effects due to atmospheric pressure, watch-glasses
were applied to the opening in the skull, and securely cemented to the
edges with Canada balsam. The phenomena observed did not differ from those
previously noticed; and, in fact, many repetitions of the experiment gave
like results.
Durham, in the next place, applied ligatures to the jugular and vertebral
veins, with the effect--as was to be expected--of producing intense
congestion of the brain, attended with coma. This last condition he very
properly separates from sleep, which is never caused by pressure from the
veins. He likens sleep to the state induced by preventing the access of
blood to the brain through the carotids, but does not allude to Fleming’s
researches on this point.
From his observations, Durham deduces the following conclusions:
“1. Pressure of distended veins upon the brain is not the cause of sleep,
for during sleep the veins are not distended; and when they are, symptoms
and appearances arise which differ from those which characterize sleep.
“2. During sleep the brain is in a comparatively bloodless condition, and
the blood in the encephalic vessels is not only diminished in quantity,
but moves with diminished rapidity.
“3. The condition of the cerebral circulation during sleep is, from
physical causes, that which is most favorable to the nutrition of the
brain tissue; and, on the other hand, the condition which prevails during
waking is associated with mental activity, because it is that which is
most favorable to oxydation of the brain substance, and to various changes
in its chemical constitution.
“4. The blood which is derived from the brain during sleep is distributed
to the alimentary and excretory organs.
“5. Whatever increases the activity of the cerebral circulation tends to
preserve wakefulness; and whatever decreases the activity of the cerebral
circulation, and, at the same time, is not inconsistent with the general
health of the body, tends to induce and favor sleep. Such circumstances
may act primarily through the nervous or through the vascular system.
Among those which act through the nervous system, may be instanced the
presence or absence of impressions upon the senses, and the presence or
absence of exciting ideas. Among those which act through the vascular
system, may be mentioned unnaturally or naturally increased or decreased
force or frequency of the heart’s action.
“6. A probable explanation of the reason why quiescence of the brain
normally follows its activity, is suggested by the recognized analogical
fact that the products of chemical action interfere with the continuance
of the action by which they are produced.”
Luys,[24] after stating the two opposite views relative to the state of
the cerebral circulation during sleep, gives his adhesion on principles of
analogy to that which holds to a diminished afflux of blood. Taking the
condition of the salivary glands during their periods of inaction as the
basis of his argument, he says:
“We are then naturally led, in making the application of known facts to
those which are yet unknown, to say that the nervous tissue and the
glandular tissue present, between themselves, the closest analogy, so far
as circulatory phenomena and the double alternation of their periods of
activity and repose are concerned. And that if the period during which the
gland reconstitutes its immediate principles corresponds to a period of
reduced activity of circulatory phenomena--to a state of relative
anæmia--and that when it functionates it is awakened to a state in which
its capillaries are turgid with blood, it is very admissible that the same
circulatory conditions should be present in the nervous tissue, and that
the period of inactivity, or of sleep, should be characterized by an
anemic state. Inversely, the period of activity or wakefulness should be
marked by an acceleration of the flow of blood, and by a kind of erethism
of the vascular element.”
Having thus, in as succinct a manner as possible, brought forward the
principal observations relative to the immediate cause of sleep, which up
to the present time have been published, I come, in the next place, to
detail the result of my own researches.
In 1854 a man came under my observation who had, through a frightful
railroad accident, lost about eighteen square inches of his skull. There
was thus a fissure of his cranium three inches wide and six inches long.
The lost portion consisted of a great part of the left parietal, and part
of the frontal, occipital, and right parietal bones. The man, who was
employed as a wood chopper, was subject to severe and frequent epileptic
fits, during which I often attended him. In the course of my treatment, I
soon became acquainted with the fact that, at the beginning of the
comatose condition which succeeded the fits, there was invariably an
elevation of that portion of the scalp covering the deficiency in the
cranium. As the stupor passed away, and sleep from which he could easily
be aroused ensued, the scalp gradually became depressed. When the man was
awake, the region of scalp in question was always nearly on a level with
the upper surface of the cranial bones. I also noticed on several
occasions that during natural sleep the fissure was deeper, and that in
the instant of awaking, the scalp covering it rose to a much higher level.
After my attention was thus drawn to this subject, I observed that in
young infants the portion of scalp covering the anterior fontanelle was
always depressed during sleep, and elevated during wakefulness.
During the summer of 1860 I undertook a series of experiments, with the
view of ascertaining the condition of the cerebral circulation during
sleep, of which the following is a brief abstract:
A medium-sized dog was trephined over the left parietal bone, close to the
sagittal suture, having previously been placed under the full anæsthetic
influence of ether. The opening made by the trephine was enlarged with a
pair of strong bone-forceps, so as to expose the dura mater to the extent
of a full square inch. This membrane was then cut away and the brain
brought into view. It was sunk below the inner surface of the skull, and
but few vessels were visible. Those which could be perceived, however,
evidently conveyed dark blood, and the whole exposed surface of the brain
was of a purple color. As the anæsthetic influence passed off, the
circulation of the blood in the brain became more active. The purple hue
faded away, and numerous small vessels filled with red blood became
visible; at the same time the volume of the brain increased, and when the
animal became fully aroused, the organ protruded through the opening in
the skull to such an extent that, at the most prominent part, its surface
was more than a quarter of an inch above the external surface of the
cranium. While the dog continued awake, the condition and position of the
brain remained unchanged. After the lapse of half an hour, sleep ensued.
While this state was coming on I watched the brain very attentively. Its
volume slowly decreased; many of its smaller blood-vessels became
invisible, and finally it was so much contracted that its surface, pale
and apparently deprived of blood, was far below the level of the cranial
wall.
Two hours subsequently the animal was again etherized, in order that the
influence of the ether upon the cerebral circulation might be observed
from the commencement. At the time the dog was awake, and had a few
minutes previously eaten a little meat and drank a small quantity of
water. The brain protruded through the opening in the skull, and its
surface was of a pink hue, with numerous red vessels ramifying over it.
The ether was administered by applying to the muzzle of the animal a towel
folded into the shape of a funnel, and containing a small sponge saturated
with the agent.
As soon as the dog commenced to inspire the ether, the appearance of the
brain underwent a change of color, and its volume became less. As the
process of etherization was continued, the color of the surface darkened
to a deep purple, and it ceased to protrude through the opening. Finally,
when a state of complete anæsthesia was reached, it was perceived that the
surface of the brain was far below the level of the cranial fissure, and
that its vessels conveyed black blood alone.
Gradually the animal regained its consciousness; the vessels resumed their
red color, and the brain was again elevated to its former position. In
this last experiment there did not appear to be any congestion of the
brain. Had this condition existed, it would have been difficult to account
for the diminution in bulk, which certainly took place. There was
evidently less blood in the cerebral tissue than there had been previously
at the etherization; but this blood, instead of being oxygenated, was
loaded with excrementitial matters, and consequently was not fitted to
maintain the brain in a condition of activity.
The following morning, the dog being quite lively, I removed the sutures
which had been placed in the skin, covering the hole in the cranium, with
the view of ascertaining the effects of chloroform upon the brain, when
introduced into the system by inhalation. Suppuration had not yet taken
place, and the parts were in good condition. The opening in the skull was
completely filled by the brain, and the surface of the latter was
traversed by a great many small vessels carrying red blood. The chloroform
was administered in the same way in which the ether had been given the
previous day.
In a few seconds the change in color of the blood circulating in the
vessels began to take place, but there was no sinking of the brain below
the level of the chasm in the skull. On the contrary, its protrusion was
greater than before the commencement of the experiment. There was thus not
only unoxygenated blood circulating to too great an extent through the
brain, but there was very decided congestion.
The foregoing experiments were frequently repeated on other dogs, and also
on rabbits, with like results. Within a short period I have in part gone
over the ground again, without observing any essential point of difference
in the effects produced.
I have never repeated Fleming’s experiment on the human subject, except in
one instance, and then sleep, or a condition resembling it, was
instantaneously produced. As soon as the pressure was removed from the
carotids, the individual gained his consciousness. On dogs and rabbits,
however, I have performed it frequently, and though if the pressure be
continued for longer than one minute, convulsions generally ensue, a state
of insensibility resembling natural sleep is always the first result.
Lately, I have had, through the kindness of my friend, Dr. Van Buren, the
opportunity of examining a case which affords strong confirmation of the
correctness of the preceding views. It was that of a lady in whom both
common carotids were tied for a cirsoid aneurism, involving a great
portion of the right side of the scalp. One carotid was tied by the late
Dr. J. Kearney Rogers, and the other by Dr. Van Buren, seven years ago,
with the effect of arresting the progress of the disease. No peculiar
symptoms were observed in consequence of these operations, except the
supervention of persistent drowsiness, which was especially well marked
after the last operation, and which, even now, is at times quite
troublesome.
We thus see that the _immediate_ cause of sleep is a diminution of the
quantity of blood circulating in the vessels of the brain, and that the
_exciting_ cause of periodical and natural sleep is the necessity which
exists that the loss of substance which the brain has undergone, during
its state of greatest activity, should be restored. To use the simile of
the steam-engine again, the fires are lowered and the operatives go to
work to repair damages and put the machine in order for next day’s work.
Whatever other cause is capable of lessening the quantity of blood in the
brain is also capable of inducing sleep. There is no exception to this
law, and hence we are frequently able to produce this condition at will.
Several of these factors have been already referred to, but it will be
interesting to consider them all somewhat more at length.
_Heat._--Most persons in our climate, and in those of higher temperatures,
have felt the influence of heat in causing drowsiness, and eventually
sleep, if the action is powerful enough and sufficiently prolonged. It is
not difficult to understand the mode by which heat acts in giving rise to
sleep. During the prevalence of high temperatures the blood flows in
increased proportion to the surface of the body and to the extremities,
and consequently the quantity in the brain is diminished. Sleep
accordingly results unless the irritation induced by the heat is so great
as to excite the nervous system. Heat applied directly to the head exerts,
of course, a directly contrary effect upon the cerebral circulation, as we
see in sun-stroke. Here there is internal cerebral congestion, loss of
consciousness, stupor, etc.
That the effect of heat is to dilate the vessels of the part subjected to
its influence, can be ascertained by putting the arm or leg into hot
water. The swelling of the blood-vessels is then very distinctly seen. It
will be shown hereafter that one of the best means of causing sleep in
morbid wakefulness is the warm-bath.
_Cold._--A slight degree of cold excites wakefulness at first, but if the
constitution be strong the effect is to predispose to sleep. This it does
by reason of the determination of blood to the surface of the body which
moderate cold induces in vigorous persons. The ruddy complexion and warmth
of the hands and feet produced in such individuals under the action of
this influence are well known.
But if the cold be very intense, or the reduction of temperature sudden,
the system, even of the strongest persons, cannot maintain a resistance,
and then a very different series of phenomena result. Stupor, not sleep,
is the consequence. The blood-vessels of the surface of the body contract
and the blood accumulates in the internal organs, the brain among them.
Many instances are on record showing the effect of extreme cold in
producing stupor and even death. One of the most remarkable of these is
that related by Captain Cook, in regard to an excursion of Sir Joseph
Banks, Dr. Solander, and nine others, over the hills of Terra del Fuego.
Dr. Solander, knowing from his experience in Northern Europe that the
stupor produced by severe cold would terminate in death unless resisted,
urged his companions to keep in motion when they began to feel drowsy.
“Whoever sits down will sleep,” said he, “and whoever sleeps will rise no
more.” Yet he was the first to feel this irresistible desire for repose,
and entreated his companions to allow him to lie down. He was roused from
his stupor with great difficulty and carried to a fire, when he revived.
Two black men of the party, whose organizations were not so robust as
those of the whites, perished. Dr. Whiting[25] relates the case of Dr.
Edward Daniel Clark, the celebrated traveler, who on one occasion came
very near losing his life by cold. He had performed divine service at a
church near Cambridge, and was returning home on horseback, when he felt
himself becoming very cold and sleepy. Knowing the danger of yielding to
the influence which was creeping over him, he put his horse into a fast
trot, hoping thereby to arouse himself from the alarming torpor. This
means proving unavailing, he got down and led his horse, walking as fast
as he could. This, however, did not long succeed. The bridle dropped from
his arm, his legs became weaker and weaker, and he was just sinking to the
ground when a gentleman who knew him came up in a carriage and rescued
him.
I have often myself noticed this effect of cold in producing numbness and
drowsiness, and on one occasion was nearly overcome by it. I was crossing
the mountain ridge between Cebolleta and Covero, in New Mexico, when the
thermometer fell in about two hours from 52° to 22° Fahrenheit. So great
was the effect upon me that if I had had much farther to go I should
probably have succumbed. As it was, I reached a rancho in time to be
relieved, though several minutes elapsed before I was able to speak. The
sensations experienced were rather agreeable than otherwise. There was a
great desire to rest and to yield to the languor which was present, and
there was a feeling of recklessness which rendered me perfectly
indifferent to the consequences. I should have dismounted from my horse
and given way to the longing for repose if I had been able to do so. I
have several times experienced very similar effects from change of air. A
few years since I was so drowsy at the sea-coast, whither I had gone from
a hot city, that it was with difficulty I could keep awake, even when
engaged in active physical exercise.
Another potent cause of sleep, and one of which we generally avail
ourselves, is the _diminution of the power of the attention_. To bring
this influence into action generally requires only the operation of the
will under circumstances favorable to the object in view. Shutting the
eyes so as to exclude light, getting beyond the sound of noises,
refraining from the employment of the other senses, and avoiding thought
of all kind, will generally, when there is no preventing cause, induce
sleep. To think, and to maintain ourselves in connection with the outward
world by means of our senses requires that the circulation of blood in the
brain shall be active. When we isolate ourselves from external things, and
restrain our thoughts, we lessen the amount of blood in the brain, and
sleep results. It is not, however, always easy for us to do this. The
nervous system is excited, ideas follow each other in rapid succession,
and we lie awake hour after hour vainly trying to forget that we exist.
The more the will is brought to bear upon the subject the more rebellious
is the brain, and the more it will not be forced by such means into a
state of quietude. We must then either let it run riot till it is worn out
by its extravagancies, or we must fatigue it by requiring it to perform
labor which is disagreeable. Just as we might do with an individual of
highly destructive propensities, who was going about pulling down his
neighbors’ houses. We might, if we were altogether unable to stop him, let
him alone till he had become thoroughly wearied with his exertions, or we
might divert him from his plan by guiding him to some tough piece of work
which would exhaust his strength sooner than would his original labor.
Many ways of thus tiring the brain have been proposed. The more irksome
they are, the more likely they are to prove effectual. Counting a hundred
backward many times, listening to monotonous sounds, thinking of some
extremely disagreeable and tiresome subject, with many other devices, have
been suggested, and have proved more or less effectual. Boerhaave[26]
states that he procured sleep by placing a brass pan in such a position
that the patient heard the sound of water which was made to fall into it,
drop by drop. In general terms, monotony predisposes to sleep. Dr.
Dickson[27] quotes Southey’s experience as related in the Doctor,[28] and
I also cannot do better than lay it before the reader, particularly as it
indicates several methods which may be more efficacious with others than
the one he found to succeed so admirably.
“I put my arms out of bed; I turned the pillow for the sake of applying a
cold surface to my cheek; I stretched my feet into the cold corner; I
listened to the river and to the ticking of my watch; I thought of all
sleepy sounds and of all soporific things--the flow of water, the humming
of bees, the motion of a boat, the waving of a field of corn, the nodding
of a mandarin’s head on the chimney-piece, a horse in a mill, the opera,
Mr. Humdrum’s conversations, Mr. Proser’s poems, Mr. Laxative’s speeches,
Mr. Lengthy’s sermons. I tried the device of my own childhood, and fancied
that the bed rushed with me round and round. At length Morpheus reminded
me of Dr. Torpedo’s Divinity Lectures, where the voice, the manner, the
matter, even the very atmosphere and the streamy candlelight were all
alike somnific; when he who, by strong effort, lifted up his head and
forced open the reluctant eyes never failed to see all around him asleep.
Lettuces, cowslip wine, poppy syrup, mandragora, hop pillows, spider’s
web pills, and the whole tribe of narcotics, up to bang and the
black-drop, would have failed,--but this was irresistible; and thus,
twenty years after date, I found benefit from having attended the course.”
Frequently the power of the attention is diminished by natural causes.
After the mind has been strained a long time in one particular direction,
and during which period the brain was doubtless replete with blood, the
tension is at last removed, the blood flows out of the brain, the face
becomes pale, and sleep ensues. It is thus, as Macnish[29] says, that “the
finished gratification of all ardent desires has the effect of inducing
slumber; hence after any keen excitement the mind becomes exhausted and
speedily relapses into this state.”
A gentleman recently under my care for a paralytic affection, informed me
that he could at any time render himself sleepy by looking for a few
minutes at a bright light, so as to fatigue the eyes, or by paying
particular attention to the noises in the street, so as to weary the sense
of hearing. It is well known that sleep may be induced by gentle frictions
of various parts of the body, and doubtless the other senses are capable
of being so exhausted, if I may use the expression, as to diminish the
power of the attention, and thus lessen the demand for blood in the brain.
As a consequence, sleep ensues.
The cutting off of sensorial impressions aids in lessening the power of
the attention and thus predisposes to sleep. Stillness, darkness, the
absence of any decided impression on the skin, and the nonexistence of
odors and flavors, accomplish this end. In these respects, however, habit
exercises great influence, and thus individuals, for instance, who are
accustomed to continual loud noises, cannot sleep when the sound is
interrupted. As we have already seen, however, the predisposition to sleep
is, in healthy persons, generally so great that when it has been long
resisted, no sensation, however strong it may be, can withstand its power.
_Digestion_ leads to sleep by drawing upon the brain for a portion of its
blood. It is for this reason that we feel sleepy after the ingestion of a
hearty dinner. A lady of my acquaintance is obliged to sleep a little
after each meal. The desire to do so is irresistible; her face becomes
pale; her extremities cold; and she sinks into a quiet slumber, which
lasts fifteen or twenty minutes. In this lady the amount of blood is not
sufficient for the due performance of all the operations of the economy.
The digestive organs imperatively require an increased quantity, and the
flow takes place from the brain; it being the organ with her which can
best spare this fluid. As a rule, persons who eat largely, and have good
digestive powers, sleep a great deal, and many persons are unable to sleep
at night till they have eaten a substantial supper. The lower animals
generally sleep after feeding, especially if the meal has been large.
_Excessive loss of blood_ produces sleep. We can very readily understand
why this should be so if we adopt the theory which has been supported in
the foregoing pages. It would be exceedingly difficult to explain the fact
upon any other hypothesis. I have seen many instances of somnolency due to
this cause. It acts not only by directly lessening the quantity of blood
in the brain, but also by so enfeebling the heart’s action as to prevent a
due supply of blood being sent to the cerebral vessels.
_Debility_ is almost always accompanied by a disposition to inordinate
sleep. The brain is one of the first organs to feel the effects of a
diminished amount of blood or a depraved quality of this fluid being
supplied, and hence, in old age, or under the influence of a deficient
quantity of food, or through the action of some exhausting disease, there
is generally more sleep than when the physical health is not deteriorated.
The action of certain medicines, and of other measures capable of causing
sleep, not coming within the range of ordinary application, will be more
appropriately considered hereafter.
CHAPTER III.
THE PHYSICAL PHENOMENA OF SLEEP.
The approach of sleep is characterized by a languor which is agreeable
when it can be yielded to, but which, when circumstances prevent this, is
far from being pleasant. Many persons are rendered irritable as soon as
they become sleepy, and children are especially liable to manifest ill
temper under the uncomfortable feelings they experience when unable to
indulge the inclination to sleep. It is somewhat difficult to analyze the
various phenomena which go to make up the condition called sleepiness. The
most prominent feelings are an impression of weight in the upper eyelids,
and of a general relaxation of the muscles of the body, but there is
besides an internal sensation of supineness, enervation, and torpor, to
describe which is by no means easy. This sluggishness is closely allied in
character if not altogether identical with that experienced before an
attack of fainting, and is doubtless due to a like cause--a deficient
quantity of blood in the brain. Along with this languor there is a general
obtuseness of all the senses, which increases the separation of the mind
from the external world, already initiated by the physical condition of
the brain. The liveliest scenes cease to engage the attention, and the
most exciting conversation no longer interests. For a time, indeed, such
circumstances may dissipate the inclination for sleep, but eventually
nature obtains the ascendency and consciousness is lost. Before this event
there is usually yawning--a phenomenon strongly indicative of a wearied
attention; the head nods and droops upon the breast, and the body assumes
that position which is most conducive to ease, comfort, and entire
muscular inactivity.
The order in which the muscles lose their power is in general well marked,
and bears a distinct relation, as Cabanis[30] has pointed out, to the
importance of their functions. Thus, the muscles which move the arms and
legs become relaxed before those which support the head, and the latter
before those which maintain the erectness of the back. This, however, is
not always the case, for, as we have already seen, individuals will
occasionally walk, and keep their position on horseback, while in a sound
sleep, and all of us have seen persons slumbering in church, their heads
dropping on their breasts, but yet firmly holding their prayer-books in
their hands under the pretense of going through the services.
As regards the senses, the sight is of course the first to be lost in
ordinary cases--the closure of the eyelids interposing a physical
obstruction to the entrance of light. Even when the eyelids have been
removed, or from disease cannot be closed, the sight, nevertheless, is the
first of the special senses to be abolished. Some animals, as the hare for
example, do not shut the eyes when asleep; but even in them the ability to
see disappears before the action of the other senses is suspended.
These latter are not altogether abolished during sleep; their acuteness is
simply lessened. Taste is the first to fade, and then the smell; hearing
follows, and touch yields last of all, and is most readily re-excited. To
awake a sleeping person, impressions made upon the sense of touch are more
effectual than attempts to arouse through any of the other senses; the
hearing comes next in order, smell next, then taste, and the sight is the
last of all in capacity for excitation.
During sleep the respiration is slower, deeper, and usually more regular
than during wakefulness. The vigor of the process is lessened, and
therefore there is a diminution of the pulmonary exhalations. In all
probability, also, the ciliated epithelium which lines the air-passages
functionates with reduced activity. Owing to this circumstance and to the
general muscular torpor which prevails, mucus accumulates in the bronchial
tubes and requires to be expectorated on awaking.
The circulation of the blood is rendered slower. The heart beats with more
regularity, but with diminished force and frequency. As a consequence the
blood is not distributed to distant parts of the body so thoroughly and
rapidly as during wakefulness, and accordingly the extremities readily
lose their heat. Owing to the reduction in the activity of the respiratory
and circulatory functions, the temperature of the whole body falls, and
coldness of the atmosphere is less easily resisted.
The functions of the several organs concerned in digestion have their
activity increased by sleep. The blood which leaves the brain, goes, as
Durham has shown, to the stomach and other abdominal viscera, and hence
the quantities of the digestive juices are augmented, and the absorption
of the nutritious elements of the food is promoted.
The urine is excreted in less quantity during sleep than when the
individual is awake and engaged in mental or physical employment, because
the wear and tear of the system is at its minimum.
The perspiration is likewise reduced in amount by sleep. In warm weather,
however, the effort to go to sleep often causes an increase in the
quantity of this excretion, just as would any other mental or bodily
exertion. This circumstance has led some writers to a conclusion the
reverse of that just expressed. Others, again, have accepted the doctrine
of Sanctorius on this point without stopping to inquire into its
correctness. This author,[31] among other aphorisms relating to sleep,
gives the following:
“Undisturbed sleep is so great a promoter of perspiration, that in the
space of seven hours, fifty ounces of the concocted perspirable matter do
commonly exhale out of strong bodies.
“A man sleeping the space of seven hours is wont, insensibly, healthfully,
and without any violence, to perspire twice as much as one awake.”
The observations of Sanctorius with his weighing chair led to a good many
important results, but they were inexact so far as the function of the
skin was concerned, in that they made no division between the loss by this
channel and that which takes place through the lungs, for by perspiration
in the above quotations he means not only the exhalation from the skin,
but the products of respiration--aqueous vapor, carbonic acid, etc. His
apparatus was, besides, very imperfect, and could not possibly have given
the delicate indications which the subject requires.
Whether the condition of sleep promotes the absorption of morbid growths
and accumulations of fluids is very doubtful. Macnish[32] contends that it
does, but _a priori_ reasoning would rather lead us to an opposite
conclusion. Deficiencies are probably more rapidly made up during sleep
than during wakefulness, and thus ulcers heal with more rapidity, owing to
the increased formation of granulations which takes place; but the
removal of tumors, etc. by natural process involves the operation of
forces the very opposite of those concerned in reparation, and observation
teaches us that sleep is a condition peculiarly favorable to the
deposition of the materials constituting morbid growths. Some writers have
alleged that sleep accelerates the absorption of dropsical effusions, but
the disappearance of such accumulations during the condition in question
is clearly due to the mechanical causes depending upon the position of the
body.
It has also been asserted that there is an exaltation of the sexual
feeling during sleep. It is difficult to arrive at any very definite
conclusion on this point, but it is probable that here again the position
of the body conjoined with the heat of the bed has much to do in producing
the erotic manifestations occasionally witnessed. Every physician who has
had much to do with cases of the kind knows that sleeping upon the back,
by which means the blood gravitates to the generative organs and to the
lower part of the spinal cord, will often give rise to seminal emissions
with or without erotic dreams, and that such occurrences may generally be
prevented by the individual avoiding the dorsal decubitus and resting upon
one side or the other while asleep. The erections which the generality of
healthy men experience in the morning before rising from bed are likewise
due to the fact that the recumbent posture favors the flow of blood to the
penis and testicles. Such erections are usually unaccompanied by venereal
desire.
The ganglionic nervous system and the spinal cord continue in action
during sleep, though generally with somewhat diminished power and
sensibility. The reflex faculty of the latter organ is still maintained,
and thus various movements are executed without the consciousness of the
brain being awakened. Somnambulism is clearly a condition of exaltation in
the functions of the spinal cord without the controlling influence of the
cerebrum being brought into action. But, aside from this rather abnormal
phenomenon, there are others which are entirely within the range of
health, and which show that the spinal cord is awake, even though the
sleep be most profound. Thus, for instance, if the position of the sleeper
becomes irksome, it is changed; if the feet become cold, they are drawn up
to a warmer part of the bed; and cases are recorded in which individuals
have risen from bed and emptied a distended bladder without awaking.
The instances brought forward in a previous chapter of persons riding on
horseback and walking during sleep show the activity of the spinal cord,
and not that the will is exercised; and Cabanis[33] is wrong in the view
which he gives of such phenomena in the following extract.
Speaking of cases like those just referred to, he says:
“These rare instances are not the only ones in which movements are
observed produced during sleep by that portion of the will which is awake;
for it is by virtue of certain direct sensations that a sleeping man moves
his arm to brush away the flies from his face, that he draws the cover
around him so as to envelop himself carefully, or that he turns in bed
till he has found a comfortable position. It is the will which during
sleep maintains the contraction of the sphincter of the bladder,
notwithstanding the effort of the urine to escape.”
Such examples as the above we now know to be instances of reflex action,
and as not, therefore, being due to the exercise of the will.
Sleep favors the occurrence of certain pathological phenomena. Thus
individuals affected with hæmorrhoids have the liability to hemorrhage
increased when they are asleep. Several instances of the kind have come
under my notice. In one the patient lost so large a quantity of blood that
syncope ensued and might have terminated fatally had not his condition
been accidentally discovered. Bleeding from the lungs is also more apt to
occur during sleep in those who are predisposed to it. Darwin states that
a man of about fifty years of age, subject to hæmorrhoids, was also
attacked with hæmoptysis three consecutive nights at about the same
hour--two o’clock--being awakened thereby from a state of very profound
sleep. He was advised to suffer himself to be roused at one o’clock, and
to leave his bed at that hour. He did so with the result not only of
entirely breaking up the hemorrhagic disposition, but also of curing
himself of very violent attacks of headache, to which he had been subject
for many years.
Epileptic fits are also more liable to occur during sleep than at other
times, a fact not always susceptible of easy explanation. In a case of
epilepsy now under my charge, this proclivity is so well marked that the
patient, a lady, scarcely ever goes to sleep without being attacked. Her
face becomes exceedingly pale just before the fit, and if then seen the
paroxysm can be entirely prevented by waking her. She is never attacked at
other times, and I am trying, with excellent results thus far, the plan of
making her sleep altogether during the day and of waking her as soon as
her face becomes pallid. It is probable that the fits in her case are due
to a diminished amount of blood in the brain, and this supposition is
strengthened by the additional fact that bromide of potassium--a substance
which, as I have shown, lessens the amount of intracranial
blood--invariably rendered her paroxysms more frequent and severe.
Sleep predisposes to attacks of gout in those who have the gouty
diathesis, and likewise favors exacerbations in several other diseases
which it is scarcely necessary to allude to specifically. The accession of
fever toward night, and the increase which takes place in pain due to
inflammation are generally associated with the approach of night, and have
no direct relation with sleep.
Certain other morbid phenomena, such as somnambulism and nightmare, which
have a necessary relation with sleep, will be more appropriately
considered in another place.
On the other hand, sleep controls the manifestations of several diseases,
especially those which are of a convulsive or spasmodic character. Thus
the paroxysms of chorea cease during sleep, as do likewise the spasms of
tetanus and hydrophobia. Headache is also generally relieved by sleep,
though occasionally it is aggravated.
CHAPTER IV.
THE STATE OF THE MIND DURING SLEEP.
We have seen that though during sleep the operations of the senses are
entirely suspended as regards the effects of ordinary impressions, the
purely animal functions of the body continue in action. The heart beats,
the lungs respire, the stomach, the intestines, and their accessory organs
digest, the skin exhales vapor, and the kidneys secrete urine. With the
central nervous system, however, the case is very different; for while
some parts retain the property of receiving impressions or developing
ideas, others have their actions diminished, exalted, perverted, or
altogether arrested.
In the first place, there is, undoubtedly, during sleep, a general torpor
of the sensorium, which prevents the appreciation of the ordinary
excitations made upon the organs of the special senses. So far as the
nerves themselves are concerned, there is no loss of their irritability or
conducting power, and the impressions made upon them are, accordingly,
perfectly well conveyed to the brain. The suspension of the operations of
the senses is not therefore due to any loss of function in the optic
nerve, the auditory nerve, the olfactory nerve, the gustatory nerve, or
the cranial or spinal nerves concerned in the sense of touch, but solely
to the inability of the brain to take cognizance of the impressions
conveyed to it. In regard to the cause of this torpor, I have given my
views in a previous chapter.
Now it must not be supposed that because mild excitations transmitted by
the nerves of the special senses are incapable of making themselves felt,
that therefore the brain is in a state of complete repose throughout all
its parts. So far from such a condition existing, there are very decided
proofs that several faculties are exercised to a degree almost equaling
that reached during wakefulness, and we know that if the irritations made
upon the senses be sufficiently strong, the brain _does_ appreciate them,
and the sleep is broken. This ability to be readily roused through the
senses constitutes one of the main differences between sleep and stupor,
upon which stress has been already laid.
Relative to the different faculties of the mind as affected by sleep,
great variations are observed. It has been thought by some authors that
several of them are really exalted above the standard attained during
wakefulness, but this is probably a wrong view. The predominance which one
or two mental qualities apparently assume is not due to any absolute
exaggeration of power, but to the suspension of the action of other
faculties, which, when we are not asleep, exercise a governing or
modifying influence. Thus, for instance, as regards the imagination,--the
faculty of all others which appears to be most increased,--we find, when
we carefully study its manifestations in our own persons, that although
there is often great brilliancy in its vagaries, that uncontrolled as it
is by the judgment, the pictures which it paints upon our minds are
usually incongruous and silly in the extreme. Even though the train of
ideas excited by this faculty when we are asleep be rational and coherent,
we are fully conscious on awaking that we are capable of doing much better
by intentionally setting the brain in action and governing it by our will
and judgment.
Owing to the fact that these two faculties of the mind are incapable of
acting normally during sleep, the imagination is left absolutely without
controlling influence. Indeed, we are often cognizant in those dreams
which take place when we are half awake, of an inability to direct it. The
impressions which it makes upon the mind are, therefore, intense, but of
very little durability. Many stories are told of its power--how problems
have been worked out, poetry and music composed, and great undertakings
planned; but if we could get at the truth, we should probably find that
the imagination of sleep had very little to do with the operations
mentioned. Indeed, it is doubtful if the mind of a sleeping person can
originate ideas. Those which are formed are, as Locke[34] remarks, almost
invariably made up of the waking man’s ideas, and are for the most part
very oddly put together; and we are all aware how commonly our dreams are
composed of ideas, or based upon events which have recently occurred to
us.
In the previous section to the one just quoted, Locke refers to the
exaggeration of ideas which form so common a feature of our mental actions
during sleep. “It is true,” he says, “we have sometimes instances of
perception while we are asleep, and retain the memory of those thoughts;
but how extravagant and incoherent for the most part they are, how little
conformable to the perfection and order of a rational being, those
acquainted with dreams need not be told.”
And yet many remarkable stories are related, which tend to show the high
degree of activity possessed by the mind during sleep. Thus it is said of
Tartini,[35] a celebrated musician of the eighteenth century, that one
night he dreamed he had made a compact with the devil, and bound him to
his service. In order to ascertain the musical abilities of his servitor,
he gave him his violin, and commanded him to play a solo. The devil did
so, and performed so admirably that Tartini awoke with the excitement
produced, and seizing his violin, endeavored to repeat the enchanting
air. Although he was unable to do this with entire success, his efforts
were so far effectual that he composed one of the most admired of his
pieces, which in recognition of its source he called the “devil’s sonata.”
Coleridge gives the following account of the composition of the fragment,
Kubla Khan:
“In the summer of 1797, the author, then in ill health, had retired to a
lonely farm-house, between Perlock and Linton, on the Exmoor confines of
Somerset and Devonshire. In consequence of a slight indisposition, an
anodyne had been prescribed, from the effects of which he fell asleep in
his chair at the moment that he was reading the following sentence, or
words of the same substance, in Purchas’s Pilgrimage: ‘Here the Khan Kubla
commanded a palace to be built, and a stately garden thereunto. And thus
ten miles of fertile ground were inclosed with a wall.’ The author
continued for about three hours in a profound sleep, at least of the
external senses, during which time he had the most vivid confidence that
he could have composed not less than from two to three hundred lines, if
that, indeed, can be called composition, in which all the images rose up
before him as _things_ with a parallel production of the corresponding
expression without any sensation or consciousness of effort. On awaking,
he appeared to himself to have a distinct recollection of the whole; and
taking his pen, ink, and paper, instantly and eagerly wrote down the
lines that are here preserved. At this moment he was unfortunately called
out by a person on business from Perlock, and detained by him above an
hour; and on his return to his room, found to his no small surprise and
mortification, that though he still retained some vague and dim
recollection of the general purport of the vision, yet with the exception
of some eight or ten scattered lines and images, all the rest had passed
away like the images on the surface of a stream into which a stone had
been cast, but, alas! without the after restoration of the latter.”
Dr. Cromwell,[36] citing the above instance of poetic inspiration during
sleep, states that, having like Coleridge taken an anodyne during a
painful illness, he composed the following lines of poetry, which he wrote
down within half an hour after awaking. These lines, though displaying
considerable imagination, are not remarkable for any other quality.
“Lines composed in sleep on the night of January 9th, 1857.
“SCENE.--_Windsor Forest._
“At a vista’s end stood the queen one day
Relieved by a sky of the softest hue;
It happen’d that a wood-mist risen new,
Had made that white which should have been blue.
A sunbeam sought on her form to play;
It found a nook in the bowery nave,
Through which with its golden stem to lave
And kiss the leaves of the stately trees
That fluttered and rustled beneath the breeze;
But it touched not her, to whom ’twas given
To walk in a white light pure as heaven.”
In the last two of these instances it is impossible to say whether the
individuals were really asleep or not, as the opium or other narcotic
taken is a very disturbing factor in both conditions, and doubtless was
the exciting cause of the activity in the imagination. No more graphic
account of the effects of opium in arousing the imagination to its highest
pitch has been written than that given by De Quincey.[37] He says:
“At night when I lay awake in bed, vast processions passed along in
mournful pomp; friezes of never-ending stories, that to my feelings were
as sad and solemn as if they were stories drawn from times before Œdipus
or Priam, before Tyre, before Memphis. And at the same time a
corresponding change took place in my dreams; a theater seemed suddenly
opened and lighted up within my brain, which presented nightly spectacles
of more than earthly splendor.” And then, after referring to the various
scenes of architectural magnificence, and of beautiful women which his
imagination conceived, and which forcibly recalls to our minds the
poetical effusions of Coleridge and Cromwell, he gives the details of
another dream, in which he heard music. “A music of preparation, of
awakening suspense; a music like the opening of the Coronation Anthem, and
which like _that_ gave the feeling of a vast march, of infinite cavalcades
filing off, and the tread of innumerable armies.”
In reference to this subject, Dr. Forbes Winslow[38] relates the following
interesting case:
“A feeble, sensitive lady, suffering from a uterine affection, writes to
us as follows concerning the influence of three or four
sixteenth-of-a-grain doses of hydrochlorate of morphia: ‘After taking a
few doses of morphia, I felt a sensation of extreme quiet and wish for
repose, and on closing my eyes, visions, if I may so call them, were
constantly before me, and as constantly changing in their aspect: scenes
from foreign lands; lovely landscapes, with tall, magnificent trees
covered with drooping foliage, which was blown gently against me as I
walked along. Then in an instant I was in a besieged city filled with
armed men. I was carrying an infant, which was snatched from me by a
soldier and killed upon the spot. A Turk was standing by with a scimitar
in his hand, which I seized, and attacking the man who had killed the
child, I fought most furiously with him and killed him. Then I was
surrounded, made prisoner, carried before a judge and accused of the
deed; but I pleaded my own cause with such a burst of eloquence (which,
by-the-by, I am quite incapable of in my right mind) that judge, jury, and
hearers acquitted me at once. Again, I was in an Eastern city visiting an
Oriental lady, who entertained me most charmingly. We sat together on rich
ottomans, and were regaled with supper and confectionery. Then came soft
sounds of music at a distance, while fountains were playing and birds
singing, and dancing girls danced before us, every movement being
accompanied with the tinkling of silver bells attached to their feet. But
all this suddenly changed, and I was entertaining the Oriental lady in my
own house, and in order to please her delicate taste, I had everything
prepared as nearly as possible after the fashion with which she had so
enchanted me. She, however, to my no small surprise, asked for wine, and
took not one, two, or three glasses, but drank freely, until at last I
became terrified that she would have to be carried away intoxicated. While
considering what course I had better adopt, several English officers came
in, and she at once asked them to drink with her, which so shocked my
sense of propriety that the scene changed and I was in darkness.
“‘Then I felt that I was formed of granite, and immovable. Suddenly a
change came again over me, and I found that I consisted of delicate and
fragile basket-work. Then I became a danseuse, delighting an audience and
myself by movements which seemed barely to touch the earth. Presently
beautiful sights came before me, treasures from the depth of the sea, gems
of the brightest hues, gorgeous shells, coral of the richest colors,
sparkling with drops of water, and hung with lovely seaweed. My eager
glances could not take in half the beautiful objects that passed before me
during the incessant changes the visions underwent. Now I was gazing upon
antique brooches and rings from buried cities; now upon a series of
Egyptian vases; now upon sculptured wood-work blackened by time; and
lastly I was buried amid forests of tall trees, such as I had read of but
never seen.
“‘The sights that pleased me most I had power to a certain extent to
prolong, and those that displeased me I could occasionally set aside, and
I awoke myself to full consciousness once or twice while under the
influence of the morphia by an angry exclamation that I would not have it.
I did not once lose my personal identity.’
“The lady almost invariably suffers more or less from hallucinations of
the foregoing character, if it becomes necessary to administer to her an
opiate: and on analyzing her visions, she can generally refer the
principal portions of them, notwithstanding their confusion and
distortion, to works that she has recently read.”
Opium, in certain doses, increases the amount of blood in the brain, and
this induces a condition very different from that of sleep. In this fact
we have an explanation of the activity of the imagination as one of its
prominent effects. That Coleridge should have composed the Kubla Khan
under its influence is in nowise remarkable. It is probable, however, that
the full influence of his mind was exerted upon it after he awoke to
consciousness, and that the wild fancies excited by the opiate, and based
upon what he had been previously reading, formed the substratum of his
conceptions. In any event, the ideas contained in this fragment are no
more fanciful than those which occurred to De Quincey and the lady whose
case has just been recorded, nor are they more impressively related.
The imagination may therefore be active during sleep, but we have no
authentic instance on record that it has, unaided by causes which exercise
a powerful influence over the intracranial circulation, led to the
production of any ideas which could not be excelled by the individual when
awake. Perhaps the most striking case in opposition to this opinion is one
detailed by Abercrombie,[39] who says:
“The following anecdote has been preserved in a family of rank in
Scotland, the descendants of a distinguished lawyer of the last age. This
eminent person had been consulted respecting a case of great importance
and much difficulty, and he had been studying it with intense anxiety and
attention. After several days had been occupied in this manner, he was
observed by his wife to rise from his bed in the night and go to a
writing-desk which stood in the bed-room. He then sat down and wrote a
long letter, which he put carefully by in the desk and returned to bed.
The following morning he told his wife that he had had a most interesting
dream; that he had dreamt of delivering a clear and luminous opinion
respecting a case which had exceedingly perplexed him, and that he would
give anything to recover the train of thought which had passed before him
in his dream. She then directed him to the writing-desk, where he found
the opinion clearly and fully written out, and which was afterwards found
to be perfectly correct.”
It is probable that this gentleman was actually awake when he arose from
the bed and wrote the paper referred to, and that in the morning he
mistook the circumstance for a dream. It is not at all uncommon for such
errors to be committed, especially under the condition of mental anxiety
and fatigue. A gentleman informed me only a short time since that going to
bed after a very exciting day he thought the next morning that he had
dreamed of a fire occurring in the vicinity of his house. To his surprise
his wife informed him that the supposed dream was a reality, and that he
had got up to the window, looked at the fire, conversed with her
concerning it, and that he was at the time fully awake.
Brierre de Boismont[40] relates the following instance, which is to the
same effect:
“In a convent in Auvergne, an apothecary was sleeping with several
persons; being attacked with nightmare, he charged his companions with
throwing themselves on him and attempting to strangle him. They all denied
the assertion, telling him that he had passed the night without sleeping,
and in a state of high excitement. In order to convince him of this fact,
they prevailed on him to sleep alone in a room carefully closed, having
previously given him a good supper, and even made him partake of food of a
flatulent nature. The paroxysm returned; but, on this occasion, he swore
that it was the work of a demon, whose face and figure he perfectly
described.”
That the imagination may in its flights during sleep strike upon fancies
which are subsequently developed by the reason into lucid and valuable
ideas, is very probable. It would be strange if from among the innumerable
absurdities and extravagancies to which it attains something fit to be
appropriated by the mind should not occasionally be evolved, and thus
there are many instances mentioned of the starting-point of important
mental operations having been taken during sleep. Some of these may be
based upon fact, but the majority are probably of the class of those just
specified, or occurred at an age of the world when a belief in the
supernatural exercised a greater power over men’s minds than it does at
the present day. Among the most striking of them are the following:
Galen declares that he owed a great part of his knowledge to the
revelations made to him in dreams. Whether this was really the case or not
we can in a measure determine by recalling the fact that he was a believer
in the prophetic nature of dreams, and states that a man having dreamt
that one of his legs was turned into stone, soon afterward became
paralytic in this limb, although there was no evidence of approaching
disease. Galen also conducted his practice by dreams, for an athlete,
having dreamt that he saw red spots, and that the blood was flowing out of
his body, was supposed by Galen to require blood-letting, which operation
was accordingly performed.
It has been said[41] that the idea of the _Divina Commedia_ occurred to
Dante during sleep. There is nothing at all improbable in this
supposition, though I have been unable to trace it to any definite source.
Cabanis[42] states that Condillac assured him that often during the course
of his studies he had to leave them unfinished in order to sleep, and that
on awaking he had more than once found the work upon which he was engaged
brought to a conclusion in his brain.
These were clearly instances of “unconscious cerebration” of that power
which the brain possesses to work out matters which have engaged its
attention, without the consciousness of the individual being aroused to a
knowledge of the labor being performed. It is not unlikely that this kind
of mental activity goes on to some extent during sleep, but as it is of
such a character that the mind does not take cognizance of its operations,
I do not see how the exact period of its performance can be ascertained.
Jerome Cardan believed that he composed books while asleep, and his case
is often adduced as an example of the height to which the imagination can
attain during sleep. But this great man was superstitious to an extreme
degree; he believed that he had a familiar spirit, from whom he received
intelligence, warnings, and ideas, and asserted that when awake he
frequently saw long processions of men, women, animals, trees, castles,
instruments of various kinds and many figures, different from anything in
this world. His evidence relative to his compositions and mathematical
labors when asleep is not therefore of a trustworthy character.
As regards the memory in sleep, it is undoubtedly exercised to a
considerable extent. In fact, whatever degree of activity the mind may
then exhibit is based upon events the recollection of which has been
retained. But there is more or less error mingled with a small amount of
truth. The unbridled imagination of the sleeper so distorts the simplest
circumstances as to render their recognition a matter of no small
difficulty, and thus it scarcely if ever happens that events are
reproduced during sleep exactly as they occurred or as they would be
recalled by the mind of the individual when awake. Frequently, also,
recent events which have made a strong impression on our minds are
forgotten, as when we dream of seeing and conversing with persons not long
dead.
And yet it has sometimes happened that incidents or knowledge which had
long been overlooked or forgotten, or which could not be remembered by any
effort during wakefulness have been strongly depicted during sleep. Thus
Lord Monboddo[43] states that the Countess de Laval, a woman of perfect
veracity and good sense, when ill, spoke during sleep in a language which
none of her attendants understood, and which even she was disposed to
regard as gibberish. A nurse detected the dialect of Brittany; her
mistress had spent her childhood in that province, but had lost all
recollection of the Breton tongue, and could not understand a word of what
she said in her dreams. Her utterances applied, however, exclusively to
the experience of childhood, and were infantile in structure.
Abercrombie[44] relates the case of a gentleman who was very fond of the
Greek language, and who, in his youth, had made considerable progress in
it. Subsequently being engaged in other pursuits, he so entirely forgot it
that he could not even read the words; often, however, in his dreams he
read Greek works, which he had been accustomed to use at college, and had
a most vivid impression of fully understanding them.
Many other instances of the action of memory during sleep might be brought
forward, but the subject will be more appropriately considered in the
chapter on dreams.
The judgment is frequently exercised when we are asleep, but almost
invariably in a perverted manner. In fact we scarcely ever estimate the
events or circumstances which appear to transpire in our dreams at their
real value, and very rarely from correct conceptions of right and wrong.
High-minded and honorable men do not scruple during sleep to sanction the
most atrocious acts, or to regard with complaisance ideas which, in their
waking moments, would fill them with horror. Delicate and refined women
will coolly enter upon a career of crime, and the minds of hardened
villains are filled with the most elevated and noble sentiments. The
deeds which we imagine we perform in our sleep are generally inadequate to
or in excess of what the apparent occasion requires, and we lose so
entirely the ideas of probability and possibility, that no preposterous
vision appears otherwise than as perfectly natural and correct. Thus, a
physician dreamed that he had been transformed into a monolith which stood
grandly and alone in the vast desert of the Sahara, and had so stood for
ages, while generation after generation wasted and melted away around him.
Although unconscious of having organs of sense, this column of granite saw
the mountains growing bald with age, the forests drooping with decay, and
the moss and ivy creeping around its crumbling base.[45]
But, although in this instance there was some conception of time, as shown
in the association of the evidences of decay with the lapse of years,
there is in general no correct idea on this subject. Without going into
details which more appropriately belong to another division of this
treatise, I quote the following remarkable example from the essay last
cited. It appeared originally in a biographical sketch of Lavalette,
published in the _Revue de Paris_, and is related by Lavalette as
occurring to him while in prison:
“One night, while I was asleep, the clock of the Palais de Justice struck
twelve and awoke me. I heard the gate open to relieve the sentry, but I
fell asleep again immediately. In this sleep I dreamt that I was standing
in the Rue St. Honore. A melancholy darkness spread around me; all was
still; nevertheless, a slow and uncertain sound soon arose. All of a
sudden, I perceived at the bottom of the street and advancing toward me, a
troop of cavalry,--the men and horses, however, all flayed. The men held
torches in their hands, the red flames of which illuminated faces without
skin, and bloody muscles. Their hollow eyes rolled fearfully in their
sockets, their mouths opened from ear to ear, and helmets of hanging flesh
covered their hideous heads. The horses dragged along their own skins in
the kennels which overflowed with blood on all sides. Pale and disheveled
women appeared and disappeared at the windows in dismal silence; low
inarticulate groans filled the air, and I remained in the street alone
petrified with horror, and deprived of strength sufficient to seek my
safety in flight. This horrible troop continued passing along rapidly in a
gallop, and casting frightful looks upon me. Their march continued, I
thought, for five hours, and they were followed by an immense number of
artillery wagons full of bleeding corpses, whose limbs still quivered; a
disgusting smell of blood and bitumen almost choked me. At length the iron
gates of the prison, shutting with great force, awoke me again. I made my
repeater strike; it was no more than midnight, so that the horrible
phantasmagoria had lasted no more than two or three minutes--that is to
say, the time necessary for relieving the sentry and shutting the gate.
The cold was severe and the watchword short. The next day the turnkey
confirmed my calculations. I, nevertheless, do not remember one single
event in my life the duration of which I have been able more exactly to
calculate, of which the details are deeper engraven on my memory, and of
which I preserve a more perfect consciousness.”
No instance can more strikingly exemplify aberration of the faculty of
judgment than the above. There was no astonishment felt with the horror
experienced, but all the impossible events which appeared to be
transpiring were accepted as facts, which might have taken place in the
regular order of nature.
An important question connected with the exercise of judgment is: does the
dreamer know that he is dreaming? Some authors assert that this knowledge
is possible, others that it is not. The following account is interesting,
and I therefore transcribe it, especially as it has not to my knowledge
been heretofore published in this country.
In a letter to the Rev. William Gregory, Dr. Thomas Reid[46] says:
“About the age of fourteen, I was almost every night unhappy in my sleep
from frightful dreams. Sometimes hanging over a frightful precipice and
just ready to drop down; sometimes pursued for my life and stopped by a
wall or by a sudden loss of all strength; sometimes ready to be devoured
by a wild beast. How long I was plagued by such dreams I do not now
recollect. I believe it was for a year or two at least; and I think they
had quite left me before I was fifteen. In those days I was much given to
what Mr. Addison in one of his Spectators calls castle-building, and, in
my evening solitary walk, which was generally all the exercise I took, my
thoughts would hurry me into some active scene, where I generally
acquitted myself much to my own satisfaction, and in these scenes of
imagination I performed many a gallant exploit. At the same time, in my
dreams, I found myself the most arrant coward that ever was. Not only my
courage, but my strength failed me in every danger, and I often rose from
my bed in the morning in such a panic that it took some time to get the
better of it. I wished very much to get free of these uneasy dreams, which
not only made me unhappy in sleep, but often left a disagreeable
impression in my mind for some part of the following day. I thought it was
worth trying whether it was possible to recollect that it was all a dream,
and that I was in no real danger. I often went to sleep with my mind as
strongly impressed as I could with this thought that I never in my
lifetime was in any real danger, and that every fright I had was a dream.
After many fruitless endeavors to recollect this when the danger appeared,
I effected it at last, and have often, when I was sliding over a precipice
into the abyss, recollected that it was all a dream, and boldly jumped
down. The effect of this commonly was, that I immediately awoke. But I
awoke calm and intrepid, which I thought a great acquisition. After this
my dreams were never very uneasy, and, in a short time, I dreamed not at
all.”
Beattie[47] states that he once dreamed that he was walking on the parapet
of a high bridge. How he came there he did not know, but recollecting that
he was not given to such pranks, he began to think it might all be a
dream, and, finding his situation unpleasant, and being desirous to get
out of it, threw himself headlong from the height, in the belief that the
shock of the fall would restore his senses. The event turned out as he
anticipated.
Aristotle also asserts that when dreaming of danger, he used to recollect
that he was dreaming, and that he ought not to be frightened.
A still more remarkable narration is that of Gassendi,[48] which he thus
relates as occurring to himself:
“A good friend of mine, Louis Charambon, judge of the criminal court at
Digne, had died of the plague. One night, as I slept, I seemed to see him;
I stretched out my arms toward him, and said, ‘Hail thou who returnest
from the place of the dead!’ Then I stopped, reflecting in my dream as
follows: ‘One cannot return from the other world; I am doubtless dreaming;
but if I dream, where am I? Not at Paris, for I came last to Digne. I am
then at Digne, in my house, in my bedroom, in my bed.’ And then, as I was
looking for myself in the bed, some noise, I know not what, awoke me.”
In all these and like instances, it is very probable the individuals were
much more awake than asleep, for certainly the power to judge correctly is
not exercised in dreams, involving even the most incongruous
impossibilities. As Dendy[49] says, “if we _know_ that we are dreaming,
the faculty of judgment cannot be inert, and the dream would be known to
be a fallacy.” There would therefore be no occasion for any such
management of it as that made use of by Reid and Beattie, or for the
recollection of Aristotle. The dream and the correction of it by the
judgment would go together and there would be no self-deception at
all--not even for an instant. Dreams would accordingly be impossible. The
essential feature of mental activity during sleep, absolute freedom of the
imagination, would not exist.
Relative to Gassendi’s case, it is impossible to believe that he was fully
asleep, and the fact that he was awakened by some noise, the nature of
which was unrecognized, and which was therefore probably slight, tends to
support this view. Moreover, although he was, as he thought, enabled to
detect the fallacy of his dream in one respect, his judgment was
altogether at fault in others. Thus he had great difficulty in making out
where he was, and actually so far lost all idea of his identity with the
person dreaming as to look for himself in his own bed! Certainly an
individual whose judgment was thus much deranged would scarcely be able to
reason correctly as to the fact of his dreaming or not, or to question the
possibility of the dead returning to this world.
My opinion therefore is, that during sleep the power of bringing the
judgment into action is suspended. We do not actually lose the power of
arriving at a decision, but we cannot exert the faculty of judgment in
accordance with the principles of truth and of correct reasoning. An
opinion may therefore be formed during sleep, but it is more likely to be
wrong than right, and no effort that we can make will enable us to
distinguish the false from the true, or to discriminate between the
possible and the impossible.
That faculty of the mind--the judgment--which when we are awake is
pre-eminently our guide, can no longer direct us aright. The stores of
experience go for naught, and the mind accepts as truth whatever
preposterous thought the imagination presents to it. We are not entirely
rendered incapable of judging, as some authors assert, but the power to
perceive the logical force of circumstances, to take them at their true
value and to eliminate error from our mental processes, is altogether
arrested, and we arrive at absurd conclusions from impossible premises.
But there is no doubt that at times the faculty of judgment is suspended
as regards some parts of our mental operations during sleep, and this, to
such an extent, that we are like Gassendi in the case quoted, not capable
of recognizing our own individuality. Thus it is related of Dr. Johnson,
that he had once in a dream a contest of wit with some other person, and
that he was very much mortified by imagining that his opponent had the
better of him. “Now,” said he, “one may mark here the effect of sleep in
weakening the power of reflection; for had not my judgment failed me, I
should have seen that the wit of this supposed antagonist, by whose
superiority I felt myself depressed, was as much furnished by me as that
which I thought I had been uttering in my own character.”
Van Goens dreamt that he could not answer questions to which his neighbor
gave correct responses.
An interesting case, in which the judgment was still more at fault, has
recently come to my knowledge.
Mrs. C. dreamed that she was Savonarola, and that she was preaching to a
vast assembly in Florence. Among the audience was a lady whom she at once
recognized to be her own self. As Savonarola, she was delighted at this
discovery, for she reflected that she was well acquainted with all Mrs.
C.’s peculiarities and faults of character, and would, therefore, be
enabled to give special emphasis to them in the sermon. She did this so
very effectively that Mrs. C. burst into a torrent of tears, and, with the
emotion thus excited, the lady awoke. It was some time before she was able
to disentangle her mixed up individualities. When she became fully awake
she perceived that the arguments she had employed to bring about the
conversion of herself were puerile in the extreme, and were directed
against characteristics which formed no part of her mental organization,
and against offenses which she had not committed.
Macario[50] makes the following apposite remarks on the point under
consideration. Referring to the preposterous nature of many dreams, he
says:
“It is astonishing that all these fantastical and impossible visions seem
to us quite natural, and excite no astonishment. This is because the
judgment and reflection having abdicated, no longer control the
imagination nor co-ordinate the thoughts which rush tumultuously through
the brain of the sleeper, combined only by the power of association.
“When I say that the judgment and reflection abdicate, it should not be
inferred that they are abolished and no longer exist, for the imagination
could not, unaided by the reason, construct the whimsical and capricious
images of dreams.”
Relative to the power to work out, during sleep, problems involving long
and intricate mental processes, I have already expressed my opinion
adversely. In this view, I am not alone. Rosenkranz,[51] whose
contributions to psychological science cannot be overestimated, and whose
clear and powerful understanding has rarely been excelled, has pointed out
how such operations of the understanding are impossible; for, as he
remarks, intellectual problems cannot be solved during sleep, for such a
thing as intense thought, accompanied by images, is unknown, whilst dreams
consist of a series of images connected by loose and imperfect reasoning.
Feuchtersleben,[52] referring with approval to this opinion of Rosenkranz,
says that he recollects perfectly having dreamt of such problems, and
being happy in their solution, endeavored to retain them in his memory; he
succeeded, but discovered, on awaking, that they were quite unmeaning, and
could only have imposed upon a sleeping imagination.
Müller[53] says:
“Sometimes we reason more or less correctly in dreams. We reflect on
problems and rejoice in their solution. But on awaking from such dreams,
the seeming reasoning is frequently found to have been no reasoning at
all, and the solution of the problem over which we had rejoiced, to be
mere nonsense. Sometimes we dream that another person proposes an enigma;
that we cannot solve it and that others are equally incapable of doing so;
but that the person who proposed it, himself gives the explanation. We are
astonished at the solution we had so long labored in vain to find. If we
do not immediately awaken and afterwards reflect on this proposition of an
enigma in our dream, and on its apparent solution, we think it wonderful;
but if we awake immediately after the dream, and are able to compare the
answer with the question, we find that it was mere nonsense.”
And in regard to the knowledge that we are dreaming, the same author[54]
observes that:
“The indistinctness of the conception in dreams is generally so great that
we are not aware that we dream. The phantasms which are perceived really
exist in our organs of sense. They afford, therefore, in themselves as
strong proof of the actual existence of the objects they represent, as
our own perceptions of real external objects in the waking state; for we
know the latter only by the affections of our senses which they produce.
When, therefore, the mind has lost the faculty of analyzing the
impressions on our senses, there is no reason why the things which they
seem to represent should be supposed unreal. Even in the waking state
phantasms are regarded as real objects when they occur to persons of
feeble intellect. On the other hand, when the dreaming approaches more
nearly to the waking state, we sometimes are conscious that we merely
dream, and still allow the dream to proceed, while we retain this
consciousness of its true nature.”
Sir Benjamin Brodie,[55] in discussing the subject of wonderful
discoveries made in dreams, and abstruse problems worked out, remarks that
it would indeed be strange if among the vast number of combinations which
constitute our dreams, there were not every now and then some having the
semblance of reality; and further, that in many of the stories of great
discoveries made in dreams, there is much of either mistake or
exaggeration, and that if they could have been written down at the time,
they would have been found to be worth little or nothing.
Another faculty exercised during sleep has been ascribed to the judgment.
It is well known that many persons having made up their minds to awake at
a certain hour invariably do so. I possess this power in a high degree,
and scarcely ever vary a minute from the fixed time. Just as I go to bed I
look at my watch and impress upon my mind the figures on the dial which
represent the hour and minute at which I wish to awake. I give myself no
further anxiety on the subject, and never dream of it, but I always wake
at the desired moment.
Now I cannot conceive what connection the judgment has with this power. In
the case of alarm clocks set to go off at a certain time, the judgment, as
Jouffroy[56] asserts, may take cognizance of the impression made upon the
ear, and establish the relation between it and the wish to awake at a
certain time. But in cases where the awaking is the result of an idea
conceived before going to sleep, and which is not subsequently recalled,
the judgment cannot act, for this faculty is only exercised upon ideas
which are submitted to it. The brain is, as it were, wound up like the
alarm clock and set to a certain hour. When that hour arrives, an
explosion of nervous force takes place, and the individual awakes.
Fosgate[57] asserts that the power of judging during sleep is probably as
good as when we are awake, for decisions are made only on the premises
presented in either case, and if those in the former condition are absurd
or unreasonable, the conclusion will likewise be faulty. But this is not
very accurate reasoning; for it is as much the province of the judgment to
determine the validity of the premises as it is to draw a conclusion from
them, and if it cannot recognize the falsity or truth of propositions the
irrational character of which would be readily perceived during
wakefulness, there is not much to be said in favor of its power.
In fact, however, the conclusions formed in dreams are often without any
logical relation with the premises. Thus, when an individual dreams, as in
the instance previously quoted, that he is a column of stone, it is
contrary to all experience to deduce therefrom the conclusion that he can
see rocks crumbling around him, and can reflect upon the mutability of all
things. The premise of his being a stone pillar being submitted to the
judgment, the proper conclusion would be that he is composed of inorganic
material, is devoid of life, and consequently not possessed of either
sensation or understanding.
Why the judgment is not properly exercised during sleep we do not know.
Dr. Philip[58] believes that in this condition ideas flow so rapidly that
they are not submitted to the full power of the judgment, and that hence
the absurdity which characterizes them is not perceived. But this
explanation is by no means satisfactory; for a merely swift succession of
ideas is no very serious bar to correct judgment, and when the thoughts
are as preposterous as those which so often occur in dreams, they present
no obstacle at all to a proper estimation of them by the healthy mind. The
cause probably resides in some alteration in the circulation of the blood
in that part of the brain which presides over the judgment, whereby its
power is suspended and the imagination left free to fill the mind with its
incongruous and fantastic images.
As regards the will, we find very opposite opinions entertained relative
to its activity; but no one, so far as I am aware, appears to have had
correct views upon the subject. Without going into a full discussion of
the views enunciated, it will be sufficient to refer to the ideas on the
point in question which have been expressed by some of the most eminent
philosophers and physiologists.
In the course of his remarks on sleep, Darwin[59] repeatedly alleges that
during this condition the action of the will is entirely suspended; but he
falls into the singular error of confounding volition with the power of
motion. Thus he says:
“When by one continued posture in sleep some uneasy sensations are
produced, we either gradually awake by the exertion of volition, or the
muscles connected by habit with such sensations alter the position of the
body; but where the sleep is uncommonly profound, and these uneasy
sensations great, the disease called the incubus or nightmare is produced.
Here the desire of moving the body is painfully exerted; but the power of
moving it, or volition, is incapable of action till we are awake.”
In consequence of this misapprehension of the nature of the will, it is
not easy to arrive at Darwin’s ideas on the subject; and the attempt is
rendered still more difficult from the fact that though he repeatedly
states that volition is entirely suspended during sleep, he yet in the
first part of the foregoing quotation makes an individual awake by the
gradual exercise of the power of the will; and then in the last part of
the same paragraph asserts that volition is incapable of action till sleep
is over.
Mr. Dugald Stewart[60] contends that during sleep the power of volition is
not suspended, but that those operations of the mind and body which depend
on volition cease to be exercised. In his opinion the will loses its
influence over all our powers both of mind and body in consequence of some
physical alteration in the system which we shall never probably be able
to explain. To show in full the views of so distinguished a philosopher as
Mr. Stewart, I quote the following extracts from his remarks on the
subject:
“In order to illustrate this conclusion [the one above stated] a little
further, it may be proper to remark that if the suspension of our
voluntary operations in sleep be admitted as a fact, there are only two
suppositions which can be formed regarding its cause. The one is that the
power of volition is suspended; the other that the will loses its
influence over those faculties of the mind and those members of the body
which during our waking hours are subjected to its authority. If it can be
shown then that the former supposition is not agreeable to fact, the truth
of the latter seems to follow as a necessary consequence.
“1. That the power of volition is not suspended during sleep, appears from
the efforts which we are conscious of making while in that situation. We
dream, for instance, that we are in danger, and we attempt to call out for
assistance. The attempt induced is in general unsuccessful, and the sounds
that we emit are feeble and indistinct; but this only confirms, or rather
is a necessary consequence of, the supposition that in sleep the
connection between the will and our voluntary operations is disturbed or
interrupted. The continuance of the power of volition is demonstrated by
the effort, however ineffectual.
“In like manner, in the course of an alarming dream we are sometimes
conscious of making an exertion to save ourselves by flight from an
apprehended danger; but in spite of all our efforts we continue in bed. In
such cases we commonly dream that we are attempting to escape and are
prevented by some external obstacle; but the fact seems to be that the
body is at that time not subject to the will. During the disturbed rest
which we sometimes have when the body is indisposed, the mind appears to
retain some power over it; but as even in these cases the motions which
are made consist rather of a general agitation of the whole system than of
the regular exertion of a particular member of it with a view to produce a
certain effect, it is reasonable to conclude that in perfectly sound sleep
the mind, although it retains the power of volition, retains no influence
whatever over the bodily organs.
“In that particular condition of the system which is known by the name of
_incubus_, we are conscious of a total want of power over the body; and I
believe the common opinion is that it is this want of power which
distinguishes the _incubus_ from all the other modifications of sleep. But
the more probable supposition seems to be that every species of sleep is
accompanied with a suspension of the faculty of voluntary motion; and that
the incubus has nothing peculiar in it but this--that the uneasy
sensations which are produced by the accidental posture of the body, and
which we find it impossible to remove by our own efforts, render us
distinctly conscious of our incapacity to move. One thing is certain, that
the instant of our awaking and of our recovering the command of our bodily
organs is one and the same.
“2. The same conclusion is confirmed by a different view of the subject.
It is probable, as was already observed, that when we are anxious to
procure sleep the state into which we naturally bring the mind approaches
to its state after sleep commences. Now it is manifest that the means
which nature directs us to employ on such occasions is not to suspend the
powers of volition, but to suspend the exertion of those powers whose
exercise depends on volition. If it were necessary that volition should be
suspended before we fall asleep, it would be impossible for us by our own
efforts to hasten the moment of rest. The very supposition of such efforts
is absurd, for it implies a continued will to suspend the acts of the
will.
“According to the foregoing doctrine with respect to the state of the mind
in sleep, the effort which is produced on our mental operations is
strikingly analogous to that which is produced on our bodily powers. From
the observations which have been already made, it is manifest that in
sleep the body is in a very inconsiderable degree, if at all, subject to
our command. The vital and involuntary motions, however, suffer no
interruption, but go on as when we are awake, in consequence of the
operation of some cause unknown to us. In like manner it would appear
that those operations of the mind which depend on our volition are
suspended, while certain other operations are at least occasionally
carried on. This analogy naturally suggests the idea that all our mental
operations which are independent of our will may continue during sleep;
and that the phenomena of dreaming may, perhaps, be produced by these,
diversified in their apparent effects in consequence of the suspension of
our voluntary powers.”
A very little reflection will suffice to convince the reader that Mr.
Stewart has altogether mistaken the nature of sleep. There is no evidence
to support his view that the body is not subject to the action of the will
during sleep. No change whatever is induced by this condition in the
nerves or muscles of the organism. The first are just as capable as ever
of conducting the nervous fluid, and the muscles do not lose any of their
contractile power. The reason why voluntary movements are not performed in
sleep is simply because the will does not act; and Mr. Stewart is again
wrong in asserting that volition is not then suspended. We do not will any
actions when we are asleep. We _imagine_ we do, and that is all. The
difficulties which encompass us in sleep are, it must be recollected,
purely imaginary, and the efforts we make to escape from them are likewise
the products of our fancy. Herein lies the main error which Mr. Stewart
has committed. He appears to accept the dream for a reality, and to
regard the seeming volitions which occur in it as actual facts; whereas
they are all entirely fictitious.
An example will serve to make this point still clearer.
Not long since I dreamed that I stood upon a very high perpendicular
table-land, at the foot of which flowed a river. I thought I experienced
an irresistible desire to approach the brink and to look down. Had I been
awake, such a wish would have been the very last to enter my mind, for I
have an instinctive dread of standing on a height. I dreamed that I threw
myself on my face and crawled to the edge of the cliff. I looked down at
the stream, which scarcely appeared to be as wide as my hand, so great was
the altitude upon which I was placed. As I looked I felt an overpowering
impulse to crawl still farther and to throw myself into the water below. I
imagined that I endeavored with all my will to resist this force, which
appeared to be acting by means altogether external to my organism. My
efforts, however, were all in vain. I could not control my movements, and
gradually I was urged farther and farther over the brink, till at last I
went down into the abyss below. As I struck the water I awoke with a
start. During my imaginary struggle I thought I experienced all the
emotions which such an event if real would have excited, and I was
painfully conscious of my utter inability to escape from the peril of my
situation. Here were circumstances such as, according to Mr. Stewart,
demonstrate the activity of volition, but at the same time show its
inability to act upon the body. But clearly they show no such thing, for
the imaginary volition was to refrain from crawling over a precipice which
did not exist, and over which, therefore, I was not hanging. Such an act
of the will if real, could not in the very nature of the real conditions
of the situation have been carried out--the volition was just as imaginary
as all the other circumstances of the dream.
Again, it is not always the case that the imaginary acts of the will are
not executed during sleep; and hence it would follow from Mr. Stewart’s
argument that the power of the will over the body is not then suspended.
Assuming for the moment that the volitions of sleep are real, as Mr.
Stewart supposes; if it can be shown that they are satisfactorily
performed, it results from his line of reasoning that the will has power
over the body during sleep. Every one who has ever dreamed has at times
had his will carried out to his entire satisfaction. He has ridden horses
when pursued, and has urged them forward with whip and spur so as to
escape from his enemies. Or he has executed the most surprising feats both
with his mind and body, and has performed voluntary deeds which have
excited the admiration of all beholders. Such acts are of course entirely
the product of the imagination, and all the volitions which accompany
them have no firmer basis than the unbridled fancy; but, according to Mr.
Stewart, they would be evidence of the power of the will over the body,--a
power which in reality does not exist; not, however, as Mr. Stewart
supposes from any impediments in the nerves or muscles, but because it is
never exerted.
So far as relates to movements performed during sleep, such as turning in
bed and assuming more comfortable positions, they have nothing whatever to
do with the will. They are dependent upon the action of the spinal cord,
an organ that is never at rest, and the functions of which were not known
as well when Dr. Darwin and Mr. Stewart wrote as they are now. The same is
true of more complex and longer-continued actions, such as those already
mentioned of individuals riding on horseback, or even walking, during
sleep.
Cabanis[61] contends that the will is not entirely suspended during sleep;
but, as will be perceived from the following quotation, he bases his
argument upon the fact that movements are produced which he attributes
erroneously to the action of the will, but which, like those previously
referred to, are accomplished by the agency of the spinal cord. He says,
speaking of the instances of persons walking while asleep:
“These rare cases are not the only ones in which during sleep movements
are produced by what remains of the will; for it is by virtue of certain
direct sensations that a sleeping man moves his arm to brush away the
flies that may be on his face, that he draws up the bedclothes so as to
cover himself carefully; or, as we have already remarked, that he turns
over and endeavors to find a more comfortable position. It is the will
which during sleep maintains the contraction of the sphincter of the
bladder, notwithstanding the effort of the urine to escape; it is the same
power which directs the action of the arm in seeking for the _vase de
nuit_, which knows where to find it, and enables the individual to use it
for several minutes and to return it to its place without being awakened.
Finally, it is not without reason that some physiologists have made the
will concur in the contraction of several muscles, the movements of which
are necessary to the maintenance of respiration during sleep.”
All these movements, and many others of a similar character, are entirely
spinal, and are altogether independent of cerebral influence. Even when we
are awake, we constantly execute muscular actions through the power of the
spinal cord, when the mind is intently occupied with other things. Take
for instance the example of a person playing on the piano, and at the same
time carrying on a conversation. Here the brain is engaged in the one act
and the spinal cord in the other. So long as the player is not expert in
the fingering of the instrument, he cannot divert his attention from his
performance; for the whole power of the mind is required for the proper
appreciation and execution of the music. But after the spinal cord has
become educated to the habit, and he has attained proficiency in the
necessary manipulations, the mind is no longer required to control the
actions and may be directed to other subjects. The arguments of Cabanis,
therefore, in favor of the partial exercise of the will during sleep, are
of no force.
But the power of the will over the muscles of the body is only one of the
ways in which this faculty is shown. It regulates the thoughts and the
manifestations of emotion when we are awake. How utterly incapable it is
of any such action during sleep we all know. A gentleman, remarkable for
the ability he possesses for controlling his feelings, tells me that when
he is asleep he frequently weeps or laughs at imaginary events, which, if
they really had occurred to him during wakefulness, would give rise to no
such disturbance. He often desires to stop these emotional manifestations,
but is entirely powerless to do so. Most individuals have had similar
experiences.
The theory that the will is in action during sleep is, therefore, to my
mind untenable. It has probably had its origin in the idea that confounds
it with desire, from which it differs so markedly that it seems strange
the distinction should ever fail of being made. Locke[62] points out very
clearly the differences between the two faculties. In fact they may be
exerted in directly opposite ways. Desire often precedes volition; but we
all, at times, will acts which are contrary to our desire, and desire to
perform others which we are unable to will.
Reid[63] writes with great perspicuity on this distinction between desire
and will. He says:
“Desire and will agree in this, that both must have an object of which we
must have some conception; and, therefore, both must be accompanied with
some degree of understanding. But they differ in several things.
“The object of desire may be anything which appetite, passion, or
affection leads us to pursue; it may be any event which we think good for
us, or for those to whom we are well affected. I may desire meat or drink,
or ease from pain. But to say that I will meat, or will drink, or will
ease from pain, is not English. There is, therefore, a distinction in
common language between desire and will. And the distinction is, that what
we will must be an action and our own action; what we desire may not be
our own action, it may be no action at all.
“A man desires that his children may be happy, and that they may behave
well. Their being happy is no action at all; their behaving well is not
his action but theirs.
“With regard to our own actions, we may desire what we do not will, and
will what we do not desire; nay, what we have a great aversion to.
“A man athirst has a strong desire to drink; but for some particular
reason he determines not to gratify his desire. A judge from a regard to
justice and to the duty of his office dooms a criminal to die; while, from
humanity or particular affection, he desires that he should live. A man
for health may take a nauseous draught, for which he has no desire, but a
great aversion. Desire, therefore, even when its object is some action of
our own, is only an incitement to will; but it is not volition. The
determination of the mind may be not to do what we desire to do. But as
desire is often accompanied by will, we are apt to overlook the
distinction between them.”
That desire is manifested during sleep there can be no doubt; and Mr.
Stewart, although insisting as he does on the distinction between this
faculty and volition, confounds them in his remarks already quoted. A
person suffering from nightmare has a most intense desire to escape from
his imaginary troubles. In my own dream, to which reference has been made,
my desire to restrain myself from crawling over the precipice was exerted
to the utmost; but the will could not be brought into action. Darwin,[64]
when he says that in nightmare “the _desire_ of moving the body is
painfully exerted, but the _power of moving it, or volition_, is incapable
of action till we awake,” makes the proper distinction between desire and
will; but, as I have already shown, confounds the latter with another very
different faculty.
From the foregoing observations it will be seen that during sleep the
three great divisions of the mind are differently affected.
1. Feeling, embracing sensation and emotion, is suspended, so far as the
first is concerned; but is in full action as regards the second. We do not
see, hear, smell, taste or enjoy the sense of touch in sleep, although the
brain may be aroused into activity and we may awake through the
excitations conveyed to it by the special senses. The emotions have full
play, unrestrained by the will and governed only by the imagination.
2. The Will or Volition is entirely suspended.
3. The Thought or Intellect is variously affected in its different powers.
The imagination is active, and the memory may be exercised to a great
extent; but the judgment, perception, conception, abstraction, and reason
are weakened, and sometimes altogether lost.
CHAPTER V.
THE PHYSIOLOGY OF DREAMS.
The subject of the foregoing chapter is so intimately connected with the
phenomena of dreaming, and I have expressed my views in regard to it at
such length, that but few psychological points remain to be considered in
the present discussion. What I have to say, therefore, in regard to the
physiology of dreaming must be read in connection with the chapter on
“_The State of the Mind during Sleep_,” in order that the whole matter may
be fully understood.
It is contended by some writers that the mind is never at rest, and that
even during the most profound sleep dreams take place, which are either
forgotten immediately, or which make no impression on the memory. That
this view is erroneous is, I think, very evident. If it were correct, the
first object of sleep--rest for the brain--would not be attained. We all
know how fatigued we are, and how indisposed to exertion the brain is,
after a night of continued dreaming, and we can easily imagine what would
be the consequences if such a condition were kept up night after night. To
say that we really do dream not only every night, but every instant of
the night, in fact always and continually when we sleep, but that we
forget our dreams as soon as they are formed, remembering solely those
which are most vivid, is making assertions which not only are without
proof, but which are impossible of proof. For if, as Locke[65] remarks,
the sleeping man on awaking has no recollection of his thoughts, it is
very certain that no one else can recollect them for him.
The observations of Locke on this point are extremely appropriate, and, to
my mind, very philosophical and logical. After insisting that, sleeping or
waking, a man cannot think without being sensible of it, he says:[66]
“I grant that the soul of a waking man is never without thought, because
it is the condition of being awake; but whether sleeping without dreaming
be not an affection of the whole man, mind as well as body, may be worth a
waking man’s consideration, it being hard to conceive that anything should
think and not be conscious of it. If the soul doth think in a sleeping man
without being conscious of it, I ask, whether during such thinking it has
any pleasure or pain, or be capable of happiness or misery? I am sure the
man is not, any more than the bed or earth he lies on, for to be happy or
miserable without being conscious of it seems to me utterly inconsistent
and impossible. Or if it be possible that the soul can, while the body is
sleeping, have its thinkings, enjoyments, and concerns, its pleasure or
pain, about which the man is not conscious of nor partakes in, it is
certain that Socrates asleep and Socrates awake is not the same person;
but his soul when he sleeps and Socrates the man, consisting of body and
soul when he is waking, are two persons, since waking Socrates has no
knowledge of or concernment for that happiness or misery of his soul which
it enjoys alone by itself while he sleeps without perceiving anything of
it, any more than he has for the happiness or misery of a man in the
Indies whom he knows not; for if we take wholly away all consciousness of
our actions and sensations, especially of pleasure and pain, and the
concernment that accompanies it, it will be hard to know wherein to place
personal identity.”
In a subsequent section of the same chapter, Locke asserts that most men
pass a great part of their lives without dreaming, and that he once knew a
scholar who had no bad memory, who told him he had never dreamed in his
life till after the occurrence of a fever in the twenty-fifth or
twenty-sixth year of his age.
Examples of persons who have not ordinarily dreamed are adduced by the
ancient writers. Pliny[67] refers to men who never dreamed. Plutarch[68]
alludes to the case of Cleon, who, in living to an advanced age, had yet
never dreamed; and Suetonius[69] declares that before the murder of his
mother he had never dreamed.
A lady who was under my care for a serious nervous affection declared to
me that she never had had but one dream in her life, and that was after
receiving a severe fall in which she struck her head.
And yet, notwithstanding the experience of every one that sleep often
happens without the accompaniment of dreams, the great majority of writers
hold the view that the brain is never at rest. Doubtless this opinion has
its origin partly in the doctrine that the mind is a something altogether
independent of and superior to the brain. They appear to be incapable of
appreciating the fact that when the brain is in a state of complete repose
there can be no mental manifestation, and that all intellectual phenomena
are the results of cerebral activity. Another cause for their belief is
the fact that they make no distinction between dreaming and thinking,
whereas it is very evident that the two are not to be placed in the same
category. Thinking is an _action_ which requires cerebral effort, and
which is undertaken with a determinate purpose. We will to think, and we
think what we please; but it is very different with our dreams, which
come and go without any power on our part to regulate or direct them. To
think requires all the faculties of the mind; to dream necessitates only
the memory and the imagination. In thinking, the brain is active in all
its parts; in dreaming, it is nearly entirely quiescent.
Writers who contend for the doctrine of constant mental activity regard
the brain as the organ or tool of the mind, a structure which the mind
makes use of in order to manifest itself. Such a theory is certain to lead
them into difficulties, and is contrary to all the teaching of physiology.
The full discussion of this question would be out of place here; I will,
therefore, only state that this work is written from the stand-point of
regarding the mind as nothing more than the result of cerebral action.
Just as a good liver secretes good bile, a good candle gives good light,
and good coal a good fire, so does a good brain give a good mind. When the
brain is quiescent there is no mind.
Lemoine[70] begins his chapter “_On the State of the Mind during Sleep_”
with the assertion that “there is no sleep for the mind.” He is obliged,
however, to admit that “when the organs of the body are benumbed by sleep,
the mind appears to be in a particular state; it seems to be submitted to
other laws than those which govern it during wakefulness; it seems to
have lost for a time its most precious faculties.”
During sleep the mind is, as he supposes, in a particular state, for, as
has been shown in the previous chapter, it has lost many of its chief
parts. The laws which govern it are, however, the same which always
regulate it. The body upon which their power is primarily exercised--the
brain--is not in the same condition during sleep as during wakefulness,
and hence the differences in the evidences of cerebral activity.
Sir William Hamilton[71] is generally considered to have determined
affirmatively the question of the continuance of the action of the brain
during sleep. He caused himself to be aroused from sleep at intervals
through the night, and invariably found that he was disturbed from a
dream, the particulars of which he could always distinctly recollect. But
a full knowledge of the subject he was investigating would have sufficed
to convince Sir William that the conclusion he drew from his experiments
was altogether fallacious. It is well known that dreams are excited by
strong impressions made upon the senses, or by irritations arising in the
internal organs. Thus Baron Trenck relates that when confined in his
dungeon he suffered the pangs of hunger almost continually, and that his
dreams at night were always of delicate meats and sumptuous repasts,
spread before him on luxuriously-furnished tables. The mere excitation of
waking a sleeping person is generally sufficient to give rise to a dream.
Maury, in his very interesting work, to which reference has already been
made, and which will hereafter be more specifically considered, adduces
many examples of dreams produced by sensorial impressions. I have myself
performed many experiments with reference to this point, and have
generally found ample confirmation of Maury’s investigations. It may
therefore, I think, be assumed, without any violence to the actual facts
of the cases, that the brain is not always in action, and that there are
times when we sleep without dreaming.
In the previous chapter the idea is sought to be conveyed that we
originate nothing in our dreams. We may conceive of things which never
existed, or of which we have heard or read, but the images we make of them
are either composed of elements familiar to us, or else are based upon
ideal representations which we have formed in our waking moments. Thus,
before the discovery of America no Europeans ever dreamed of American
Indians, for the reason that nothing existed within their knowledge which
could give any idea of the appearance of such human beings. It is possible
that Columbus and his companions may have dreamed of the continent of
which they were in search and of its natives, but the images formed of the
latter must necessarily have resembled other beings they had seen, or
which they had heard described. After the discovery, however, it was no
unusual thing for the Spaniards and others to have correct images of
Indians appear to them in their dreams.
Dreams, therefore, must have a foundation, and this is either impressions
made upon the mind at some previous period, or produced during sleep by
bodily sensations. These impressions, however they may be formed, are
subjected to the unrestrained influence of the imagination.
At first sight it may seem that we often have dreams not excited by actual
sensations, and which have no relation to any events of our lives, or any
ideas which have passed through our minds, but thorough investigation will
invariably reveal the existence of an association between the dream and
some such ideas or events. For instance, a few nights ago I dreamed that a
gentleman, a friend of mine, had invented what he called a “dog-cart
ambulance,” a vehicle which he declared was the best ever made for the
transportation of sick or wounded men. On awaking, all the particulars
were fresh in my mind, but I could not for some time perceive why I had
had such a dream. At last I recollected that the morning before a
gentleman had given me a very full description of Prospect Park, in
Brooklyn. The friend of whom I dreamed has charge of the construction of
this Park. His presence was, therefore, fully explained, and as dog-carts
are driven in parks, this link was also accounted for. The ambulance part
was due to the fact that I had that same morning found the card of a
gentleman upon my table who really had invented an ambulance. The
imagination had, therefore, taken these data supplied by the memory, and
had combined them into the incongruous web constituting my dream.
Dreams are also frequently built upon circumstances which have transpired
many years previously, and which have long since apparently passed from
our recollection. A very striking instance of this kind is related by
Abercrombie,[72] on the authority of Sir Walter Scott.
“Mr. R. J. Rowland, a gentleman of landed property in the vale of Gala,
was prosecuted for a very considerable sum, the accumulated arrears of
teind (tithe), for which he was said to be indebted to a noble family the
titulars (lay impropriators of the tithe). Mr. R. was strongly impressed
with the belief that his father had, by a form of process peculiar to the
law of Scotland, purchased these teinds from the titular, and, therefore,
that the present prosecution was groundless. But after an industrious
search among his father’s papers, an investigation of the public records,
and a careful inquiry among all persons who had transacted law business
for his father, no evidence could be discovered to support his defense.
The period was now near at hand when he conceived the loss of his lawsuit
to be inevitable, and he had formed his determination to ride to Edinburgh
next day, and make the best bargain he could in the way of compromise. He
went to bed with this resolution, and, with all the circumstances of the
case floating upon his mind, had a dream to the following purpose. His
father, who had been many years dead, appeared to him, he thought, and
asked him why he was disturbed in his mind. In dreams men are not
surprised at such apparitions. Mr. R. thought that he informed his father
of the cause of his distress, adding that the payment of a considerable
sum of money was the more unpleasant to him, because he had a stray
consciousness that it was not due, though he was unable to recover any
evidence in support of his belief. ‘You are right, my son,’ replied the
paternal shade; ‘I did acquire right to these teinds, for payment of which
you are now prosecuted. The papers relating to the transaction are in the
hands of Mr. ----, a writer (or attorney), who is now retired from
professional business, and resides at Inveresk, near Edinburgh. He was a
person whom I employed on that occasion for a particular reason, but who
never, on any other occasion, transacted business on my account. It is
very possible,’ pursued the vision, ‘that Mr. ---- may have forgotten a
matter which is now of a very old date; but you may call it to his
recollection by this token--that when I came to pay his account there was
difficulty in getting change for a Portugal piece of gold, and that we
were forced to drink out the balance at a tavern.’
“Mr. R. awaked in the morning with all the events of the vision impressed
on his mind, and thought it worth while to ride across the country to
Inveresk, instead of going straight to Edinburgh. When he came there he
waited on the gentleman mentioned in the dream, a very old man; without
saying anything of the vision, he inquired whether he remembered having
conducted such a matter for his deceased father. The old gentleman could
not at first bring the circumstance to his recollection, but, on mention
of the Portugal piece of gold, the whole returned upon his memory; he made
an immediate search for the papers and recovered them, so that Mr. R.
carried to Edinburgh the documents necessary to gain the cause which he
was on the verge of losing.”
A friend has related to me some circumstances in his own case similar to
the above, and illustrating the same points. In the course of his practice
as a lawyer, it became necessary for him to ascertain the exact age of a
client, who was also his cousin. Their grandfather had been a rather
eccentric personage, who had taken a great deal of notice of both his
grandsons--his only direct descendants. He died when they were boys. My
friend often told his cousin that if his grandfather were alive there
would be no difficulty at getting at the desired information, and that he
had a dim recollection of having seen a record kept by the old gentleman,
and of there being some peculiarity about it which he could not recall.
Several months elapsed, and he had given up the idea of attempting to
discover the facts of which he had been in search, when, one night, he
dreamed that his grandfather came to him and said: “You have been trying
to find out when J---- was born; don’t you recollect that one afternoon
when we were fishing I read you some lines from an Elzevir Horace, and
showed you how I had made a family record out of the work by inserting a
number of blank leaves at the end? Now, as you know, I devised my library
to the Rev. ---- ----. I was a d----d fool for giving him books which he
will never read! Get the Horace, and you will discover the exact hour at
which J---- was born.” In the morning all the particulars of this dream
were fresh in my friend’s memory. The reverend gentleman lived in a
neighboring city; my friend took the first train, found the copy of
Horace, and at the end the pages constituting the family record, exactly
as had been described to him in the dream. By no effort of his memory,
however, could he recollect the incidents of the fishing excursion.
Dr. Macnish,[73] in stating his opinion that dreams are uniformly the
resuscitation or re-embodiment of thoughts which have formerly, in some
shape or other, occupied the mind, relates the following example from his
own experience:
“I lately dreamed that I walked upon the banks of the great canal in the
neighborhood of Glasgow. On the side opposite to that on which I was, and
within a few feet of the water, stood the splendid portico of the Royal
Exchange. A gentleman whom I knew was standing upon one of the steps, and
we spoke to each other. I then lifted a large stone and poised it in my
hand, when he said that he was certain I could not throw it to a certain
spot, which he pointed out. I made the attempt, and fell short of the
mark. At this moment a well-known friend came up, whom I knew to excel at
_putting_ the stone; but, strange to say, he had lost both his legs, and
walked upon wooden substitutes. This struck me as exceedingly curious, for
my impression was that he had only lost one leg, and had but a single
wooden one. At my desire he took up the stone, and, without difficulty,
threw it beyond the point indicated by the gentleman upon the opposite
side of the canal. The absurdity of this dream is extremely glaring, and
yet, on strictly analyzing it, I find it to be wholly composed of ideas
which passed through my mind on the previous day, assuming a new and
ridiculous arrangement. I can compare it to nothing but to cross reading
in the newspapers, or to that well-known amusement which consists in
putting a number of sentences, each written on a separate piece of paper,
into a hat, shaking the whole, then taking them out, one by one, as they
come, and seeing what kind of medley the heterogeneous compound will make
when thus fortuitously put together. For instance, I had, on the above
day, taken a walk to the canal along with a friend. On returning from it,
I pointed out to him a spot where a new road was forming, and where, a few
days before, one of the workmen had been overwhelmed by a quantity of
rubbish falling upon him, which fairly chopped off one of his legs, and so
much damaged the other that it was feared amputation would be necessary.
Near this very spot there is a park, in which, about a month previously, I
practiced throwing the stone. On passing the Exchange, on my way home, I
expressed regret at the lowness of its situation, and remarked what a fine
effect the portico would have were it placed upon more elevated ground.
Such were the previous circumstances, and let us see how they bear upon
the dream. In the first place, the canal appeared before me. 2. Its
situation is an elevated one. 3. The portico of the Exchange occurring to
my mind as being placed too low became associated with the elevation of
the canal, and I placed it close by on a similar altitude. 4. The
gentleman I had been walking with was the same whom in the dream I saw
standing upon the steps of the portico. 5. Having related to him the story
of the man who lost one limb and had a chance of losing another, this idea
brings before me a friend with a pair of wooden legs, who, moreover,
appears in connection with patting the stone, as I knew him to excel at
that exercise. There is only one other element in the dream which the
preceding events will not account for, and that is the surprise at the
individual referred to having more than one wooden leg. But why should he
have even one, seeing that in reality he is limbed like other people? This
also I can account for. Two years ago he slightly injured his knee while
leaping a ditch, and I remember jocularly advising him to get it cut off.
I am particular in illustrating this point with regard to dreams, for I
hold that if it were possible to analyze them all, they would invariably
be found to stand in the same relation to the waking state as the above
specimen. The more diversified and incongruous the character of a dream,
and the more remote from the period of its occurrence the circumstances
which suggested it, the more difficult does its analysis become; and, in
point of fact, this process may be impossible, so totally are the elements
of the dream often dissevered from their original sense, and so
ludicrously huddled together.”
A dream which Professor Maas,[74] of Halle, relates as having occurred to
himself, affords an excellent example of the dependence of dreams upon
actual events, and shows how these latter are distorted and perverted by
the imagination of the sleeper.
“I dreamed once,” he says, “that the Pope visited me. He commanded me to
open my desk, and he carefully examined all the papers it contained. While
he was thus employed, a very sparkling diamond fell out of his triple
crown into my desk, of which, however, neither of us took any notice. As
soon as the Pope had withdrawn I retired to bed, but was soon obliged to
rise on account of a thick smoke, the cause of which I had yet to learn.
Upon examination I discovered that the diamond had set fire to the papers
in my desk, and burned them to ashes.”
In analyzing the circumstances which gave rise to this dream, Professor
Maas relates the following events, which constituted its basis:
“On the preceding evening I was visited by a friend with whom I had a
lively conversation upon Joseph II.’s suppression of monasteries and
convents. With this idea, though I did not become conscious of it in the
dream, was associated the visit which the Pope publicly paid the Emperor
Joseph, at Vienna, in consequence of the measures taken against the
clergy; and with this again was combined, however faintly, the
representation of the visit which had been paid me by my friend. These two
events were, by the subreasoning faculty, compounded into one, according
to the established rule--that things which agree in their parts also
correspond as to the whole; hence the Pope’s visit was changed into a
visit paid to me. The subreasoning faculty, then, in order to account for
this extraordinary visit, fixed upon that which was the most important
object in my room--namely, the desk, or rather the papers which it
contained. That a diamond fell out of the triple crown was a collateral
association, which was owing merely to the representation of the desk.
Some days before, when opening the desk, I had broken the crystal of my
watch, which I held in my hand, and the fragments fell among the papers;
hence no further attention was paid to the diamond being a representation
of a collateral series of things. But afterwards the representation of the
sparkling stone was again excited, and became the prevailing idea; hence
it determined the succeeding association. On account of its similarity it
excited the representation of fire, with which it was confounded; hence
arose fire and smoke. But in the event the writings only were burned, not
the desk itself, to which, being of comparatively little value, the
attention was not directed.”
Feuchtersleben[75] takes the same view of dreaming as that enunciated in
this chapter. Thus he says:
“Dreaming is nothing more than the occupation of the mind in sleep with
the pictorial world of fancy. As the closed or quiescent senses afford it
no materials, the mind, ever active, must make use of the store which
memory retains; but as its motor influence is likewise organically
impeded, it cannot independently dispose of this store. Thus arises a
condition in which the mind looks, as it were, on the play of the images
within itself, and manifests only a faint or partial reaction.”
Locke[76] contends that “the dreams of a sleeping man are all made up of
the waking man’s ideas oddly put together.”
Observation and reflection show us that the mind originates nothing during
sleep; it merely remembers--and often in the most chaotic manner--the
thoughts, the fancies, the impressions which have been imagined or
received by the individual when awake. Sometimes ideas are reproduced in
dreams exactly as they have occurred to us in our waking moments, and this
may take place night after night with scarcely the alteration of a single
circumstance. A friend informs me that he is very subject to dreams of
this character, and that on some occasions the repetition has taken place
as many as a dozen times.
A very striking instance of this kind occurred to me a few years since,
and made a deep impression on my mind. I had just read Schiller’s ode to
Laura, as translated by Sir E. Bulwer Lytton, beginning,
“Who and what gave to me the wish to woo thee?”
and admired it as a striking piece of versification conveying some noted
philosophical ideas in a forcible and beautiful manner. The following
night I had a very vivid dream of a condition of pre-existence, in which I
imagined myself to be. The connection between the dream and the poem I had
been reading was sufficiently well marked, and did not astonish me. I was,
however, surprised to find that the next night I had exactly the same
dream, and that it was repeated three times subsequently on consecutive
nights.
The dependence of dreams upon ideas which we have had when awake was well
known to the ancients. Thus Lucius Accius,[77] a poet who lived more than
a hundred and fifty years before the Christian era, says:
“Quae in vita usurpant homines, cogitant, curant, vident
Quaeque agunt vigilantes, agitantque casi cui in somno accidant,
* * * * * * Minus mirum est.”
Lucretius[78] declares that during sleep we are amused with things which
have made us weep when awake; that circumstances which have pleased us are
recalled to our minds; that objects are presented to us which occupied our
thoughts long before; and that recent events appear still more vividly
before us.
Petronius Arbiter[79] cites Epicurus to the same effect. Tryphæna having
declared that she had had a dream in which there appeared to her the image
of Neptune she had seen at Baiæ, “Hence you may perceive,” observed
Eumolpus, “what a divine man is Epicurus, who so ingeniously ridiculed
these sports of fancy.
“When in a dream presented to our view
Those airy forms appear so like the true,
No prescient shrine, no god the vision sends,
But every breast its own delusion lends.
For when soft sleep the body wraps in ease,
And from the inactive mass the fancy frees,
What most by day affects, at night returns;
Thus he who shakes proud states, and cities burns,
Sees showers of darts, forced lines, disordered wings,
Blood-reeking fields, and deaths of vanquished kings;
He that by day litigious knots untied,
And charmed the drowsy bench to either side,
By night a crowd of cringing clients sees,
Smiles on the fools and kindly takes their fees;
The miser hides his wealth, new treasure finds;
Through echoing woods his horn the huntsman winds;
The sailor’s dream wild scenes of wreck describes;
The wanton lays her snares; the adultress bribes;
Hounds in full cry, in sleep, the hare pursue;
And hapless wretches their old griefs renew.”[80]
It is related of an ancient tyrant that one of his courtiers described to
him a dream in which the courtier had assassinated his master. “You could
not,” exclaimed the tyrant, “have dreamed this without having previously
thought of it,” and then ordered his immediate execution.
Now besides this foundation of dreams upon circumstances which have
transpired during our waking moments, they may arise, as has already been
intimated, from impressions made upon the mind during sleep. Sensations
may be so intense as to be partially appreciated by the brain, and yet not
strong enough to cause sleep to be interrupted. In such cases the
imagination seizes the imperfect perception and weaves it into a tissue of
incongruous fancies, which, however, generally bear a more or less
definite relation to the character of the sensorial impression. Many
examples of dreams thus produced are on record, and many others have come
under my own observation. The interest which attaches to phenomena of this
character must be my excuse for quoting some of the more remarkable
instances of this kind which have been brought to my attention.
The following are related by Abercrombie:[81]
During the alarm excited in Edinburgh by the apprehension of a French
invasion almost every man was a soldier, and all things had been arranged
in expectation of the landing of the enemy. The first notice was to be
given by the firing of a gun from the Castle, and this was to be followed
by a chain of signals calculated to arouse the country. The gentleman to
whom the dream occurred was a zealous volunteer, and, being in bed between
two and three o’clock in the morning, dreamt of hearing the signal gun. He
imagined that he went at once to the Castle, witnessed the proceeding for
displaying the signals, and saw and heard all the preparations for the
assemblage of the troops. At this time he was roused by his wife, who
awoke in a fright, in consequence of a similar dream. The origin of both
dreams was ascertained in the morning to be the noise produced by the
falling of a pair of tongs in the room above.
A gentleman dreamt that he had enlisted as a soldier, joined his regiment,
deserted, was apprehended, carried back, condemned to be shot, and at last
led out to execution. At this instant a gun was fired, and he awoke, to
find that a noise in the adjoining room had both produced the dream and
awakened him.
The next is a very extraordinary case.
The subject was an officer in the expedition to Louisburg, in 1758. During
his passage in the transport his companions were in the habit of amusing
themselves at his expense. They could produce in him any kind of dream by
whispering in his ear, especially if this was done by a friend with whose
voice he was familiar. Once they conducted him through the whole process
of a quarrel which ended in a duel, and when the parties were supposed to
have met a pistol was put into his hand, which he fired, and was awakened
by the report. On another occasion they found him asleep on the top of a
locker in the cabin, when they made him believe he had fallen overboard,
and exhorted him to save himself by swimming. Then they told him that a
shark was pursuing him, and entreated him to dive for his life. He
instantly did so, and with so much force as to throw himself from the
locker upon the cabin floor, by which he was much bruised, and awakened of
course. After the landing of the army at Louisburg, his friends found him
one day asleep in his tent, and evidently much annoyed by the cannonading.
They then made him believe that he was engaged, when he exhibited great
fear, and showed a decided disposition to run away. Against this they
remonstrated, but at the same time increased his fears by imitating the
groans of the wounded and the dying; and when he asked, as he often did,
who was hit, they named his particular friends. At last they told him that
the man next himself in his company had fallen, when he instantly sprang
from his bed, rushed out of his tent, and was roused from his danger and
his dream by falling over the tent-cords.
A friend informs me that he has a brother who will carry on a conversation
with any person who whispers to him in his sleep, and that his emotions
are then very readily excited by any pitiful story that may be told him.
Upon awaking, he has a distinct recollection of his dreams, which are
always connected with the ideas communicated.
I recollect very distinctly the particulars of a dream which I had several
years since, and which was due to an impression conveyed to the brain
through the ear. The dream also illustrates the point previously brought
forward, that a definite conception of time does not enter into the
phenomena of dreams.
I dreamed that I had taken passage in a steamboat from St. Louis to New
Orleans. Among the passengers was a man who had all the appearance of
being very ill with consumption. He looked more like a ghost than a human
being, and moved noiselessly among the passengers, noticing no one, though
attracting the attention of all. For several days nothing was said between
him and any one, till one morning, as we approached Baton Rouge, he came
to where I was sitting on the guards and began a conversation by asking me
what time it was. I took out my watch, when he instantly took it from my
hand and opened it. “I, too, once had a watch,” he said; “but see what I
am now.” With these words he threw aside the large cloak he habitually
wore, and I saw that his ribs were entirely bare of skin and flesh. He
then took my watch, and, inserting it between his ribs, said it would make
a very good heart. Continuing his conversation he told me that he had
resolved to blow up the vessel the next day, but that as I had been the
means of supplying him with a heart he would save my life. “When you hear
the whistle blow,” he said, “jump overboard, for in an instant afterward
the boat will be in atoms.” I thanked him, and he left me. All that day
and the next I endeavored to acquaint my fellow-passengers with the fate
in store for them, but discovered that I had lost the faculty of speech. I
tried to write, but found that my hands were paralyzed. In fact I could
adopt no means to warn them. While I was making these ineffectual efforts,
I heard the whistle of the engine; I rushed to the side of the boat to
plunge overboard, and awoke. The whistle of a steam saw-mill near my house
had just begun to sound, and had awakened me. My whole dream had been
excited by it, and could not have occupied more than a few seconds.
The following account[82] shows how a dream may be set in action by the
sense of smell.
“On one occasion during my residence at Birmingham I had to attend many
patients at Coventry, and for their accommodation I visited that place one
day in every week. My temporary residence was at a druggist’s shop in the
market-place. Having on one occasion, now to be mentioned, a more than
usual number of engagements, I was obliged to remain one night, and a bed
was provided for me at the residence of a cheesemonger in the same
locality. The house was very old, the rooms very low, and the street very
narrow. It was summer-time, and during the day the cheesemaker had
unpacked a box or barrel of strong old American cheese; the very street
was impregnated with the odor. At night, jaded with my professional
labors, I went to my dormitory, which seemed filled with a strong, cheesy
atmosphere, which affected my stomach greatly, and quite disturbed the
biliary secretions. I tried to produce a more agreeable atmosphere to my
olfactory sense by smoking cigars, but did not succeed. At length, worn
out with fatigue, I tried to sleep, and should have succeeded, but for a
time another source of annoyance prevented me doing so; for in an old wall
behind my head, against which my ancient bed stood, there were numerous
rats gnawing away in real earnest. The crunching they made was indeed
terrific, and I resisted the drowsy god from a dread that these voracious
animals would make a forcible entrance, and might take personal liberties
with my flesh.
“But at length ‘tired nature’ ultimately so overpowered me that I slept in
a sort of fever. I was still breathing the cheesy atmosphere, and this,
associated with the marauding rats, so powerfully affected my imagination
that a most horrid dream was the consequence. I fancied myself in some
barbarous country, where, being charged with a political offense, I was
doomed to be incarcerated in a large cheese. And although this curious
prison-house seemed most oppressive, it formed but part of my sufferings;
for scarcely had I become reconciled to my probable fate than to my horror
an army of rats attacked the monster cheese, and soon they seemed to have
effected an entrance, and began to fix themselves in numbers upon my naked
body. The agony I endured was increased by the seeming impossibility to
drive them away, and, fortunately for my sanity, I awoke, but with a hot
head and throbbing temples, and a sense of nausea from the extremely
strong odor of the cheese.”
I have on two occasions that I recollect had dreams which were due to
odors. On one of them the smell of gas escaping in the room excited the
dream of a chemical laboratory; on the other the smell of burning cloth
caused me to dream of a laundry, and of one of the women ironing a
blanket, which she scorched with a hot iron. A lady informs me that a
similar odor produced in her a dream of the house being on fire and the
impossibility of her escaping by reason of all her clothes being burned
up.
Dreams are very readily excited through impressions made on the special
nerves of sensation. Instances are given of persons sleeping with bottles
of hot water applied to their feet dreaming of walking on burning lava, or
some other hot substance. A patient related to me the particulars of a
dream which occurred to him while he was asleep with a vessel of hot water
applied to the soles of his feet. He had, just before going to sleep,
read in the evening paper an account of the capture of an English
gentleman by Italian brigands. He dreamt that while crossing the Rocky
Mountains he had been attacked by two Mexicans, who, after a long fight,
had succeeded in taking him alive. They conveyed him very hurriedly to
their camp, which was situated in a deep gorge. Here they told him that
unless he revealed to them the means of making gold from copper they would
submit him to torture. In vain he plead ignorance of any such process.
Pulling off his boots and stockings they held his naked feet to the fire
till he shrieked with agony, and awoke to find that the blanket which was
wrapped around the tin vessel containing the hot water had become
disarranged, and that his feet were in direct contact with the hot metal.
In another case, that of a lady whose lower limbs were paralyzed,
artificial heat was applied during the night to her feet. Frequently her
dreams had reference to this circumstance. On one occasion she dreamed
that she was transformed into a bear, and was being taught to dance by
being made to stand on hot plates of iron. On another, that the house was
on fire, and that the floors were so hot as to burn her feet in her
efforts to escape. Again, that she was wading through a stream of water
which came from a hot spring in the Central Park.
Another patient, a lady, subject to neuralgic attacks of great severity,
frequently had the lancinating pains give rise to dreams in which she was
stabbed with daggers, cut with knives, torn with pincers, etc.
Not long since I had an attack of erysipelas, in which the disease
included the head and face. The pain was not severe, and yet it was
sufficient to give rise to the following dream:
I dreamed that I was taking a cold bath, and that while thus engaged a
Turk, armed with a pair of long pincers, came into the room and began to
pull the hair out of my head. I remonstrated, but was unable to offer any
material resistance, for the reason that the water in which I was lying
suddenly froze, leaving me imbedded in a solid cake of ice. In order to
facilitate his operations, the Turk sponged my head with boiling water,
and then, finding the use of the pincers rather slow work, shaved the hair
off with a red-hot razor. He then rubbed an ointment on the naked scalp,
composed of sulphur, phosphorus, and turpentine, to which he immediately
applied fire. Taking me in his arms he rushed down stairs into the street,
lighting his way with the flame from my burning head. He had not gone far
before he fell down in a fit, and in his struggles gave me a severe blow
between the eyes which instantly deprived me of sight.
When I awoke in the morning I had a very distinct recollection of this
dream. The incidents were in part due to the fact that I had, two or three
days previously, been reading an account of the insanity of Mohammed, and
of his being subject to attacks of epilepsy.
The sense of taste is not, for obvious reasons, so productive of dreams as
the other senses, but the experiments of M. Maury and myself, to which
fuller reference will presently be made, show that strong excitations made
upon it are transmitted to the brain; and the following instance, which
has recently come under my immediate observation, is an interesting case
in point.
A young lady had, in her early childhood, contracted the habit of going to
sleep with her thumb in her mouth. She had tried for several years to
break herself of the practice, but all her attempts were in vain, for even
when by strong mental effort she succeeded in getting to sleep without the
usual accompaniment, it was not long before the unruly member was in its
accustomed place. Finally she hit upon the plan of covering the offending
thumb with extract of aloes just before she went to bed, hoping that if
she put it into her mouth she would instantly awake. But she slept on
through the night, and in the morning found her thumb in her mouth and all
the extract of aloes sucked off. During the night, however, she dreamed
that she was crossing the ocean in a steamer made of wormwood, and that
the vessel was furnished throughout with the same material. The plates,
the dishes, tumblers, chairs, tables, etc. were all of wormwood, and the
emanations so pervaded all parts of the ship that it was impossible to
breathe without tasting the bitterness. Everything that she ate or drank
was likewise, from being in contact with wormwood, so impregnated with the
flavor that the taste was overpowering. When she arrived at Havre she
asked for a glass of water for the purpose of washing the taste from her
mouth, but they brought her an infusion of wormwood, which she gulped down
because she was thirsty, though the sight of it excited nausea. She went
to Paris and consulted a famous physician, M. Sauve Moi, begging him to do
something which would extract the wormwood from her body. He told her
there was but one remedy, and that was ox gall. This he gave her by the
pound, and in a few weeks the wormwood was all gone, but the ox gall had
taken its place, and was fully as bitter and disagreeable. To get rid of
the ox gall she was advised to take counsel of the Pope. She accordingly
went to Rome, and obtained an audience of the Holy Father. He told her
that she must make a pilgrimage to the plain where the pillar of salt
stood, into which Lot’s wife was transformed, and must eat a piece of the
salt as big as her thumb. During her journey in search of the pillar of
salt she endured a great many sufferings, but finally triumphed over all
obstacles, and reached the object of her journey. What part to take was
now the question. After a good deal of deliberation she reasoned that as
she had a bad habit of sucking her thumb, it would be very philosophical
to break off this part from the statue, and thus not only get cured of
the bitterness in her mouth, but also of her failing. She did so, put the
piece of salt into her mouth, and awoke to find that she was sucking her
own thumb.
It might be supposed that the brain during sleep is not excitable through
the sense of sight. Many examples, however, are on record of dreams being
thus produced, and several very interesting cases have come under my own
observation. Among them are the following:
A gentleman of a nervous and irritable disposition informed me that he had
dreamed of being in heaven and being dazzled by the brilliancy of
everything around him. So great was the light that he hastened to escape
from the pain which it caused in his eyes. In the efforts which he made he
struck his head against the bedpost, and awoke to find that the fire which
he had left smouldering on the hearth had kindled into a bright flame, the
light from which fell full in his face.
Another, who had been under my care for epilepsy, dreamed that his room
was entered by burglars, and that with lighted candles in their hands they
were searching his drawers and trunks. He related his dream the following
morning, and was told by his mother that she had gone into his room the
previous night, and had held a lighted candle close to his face in order
to see whether or not he was sound asleep.
No one has more philosophically studied the mode of production of dreams
than M. Maury[83] in his remarkable work to which reference has already
been made. I propose, therefore, to place a brief outline of his
experiments and views before the reader.
Just before falling asleep, and immediately before becoming fully awake,
many persons are subject to hallucinations partaking of many of the
characteristics belonging to dreams. To them the name of hypnagogic
(ῦπνος, _sleep_, and ἀγωγεύς, _leader_) hallucinations has been given,
_i.e._ hallucinations which lead to sleep. Previous to M. Maury’s
investigations, the phenomena in question had attracted some attention
from German and French physiologists, but M. Maury’s investigations, many
of which were performed upon himself, throw more light upon the subject
than it has hitherto received.
According to M. Maury, the persons who most frequently experience these
hypnagogic hallucinations are those who are of an excitable constitution,
and are generally predisposed to hypertrophy of the heart, pericarditis,
and cerebral affections. This may be true, but in two most remarkable
instances which have come under my observation, the type of organization
was the very reverse of this.
In M. Maury’s own case he finds that the hallucinations are more numerous
and more vivid when he experiences, as is frequent with him, a disposition
to cerebral congestion. Thus, when he has headache, nervous pains in the
eyes, the ears, and the nose, and vertigo, the hallucinations make their
appearance as soon as he closes his eyelids. Loss of sleep and severe
intellectual exertions invariably produce them, as do also _cafe noir_ and
champagne, which, by causing headache and insomnia, strongly predispose
him to the hypnagogic hallucinations. On the contrary, calmness of mind,
rest, and country air lessen his liability to them. From the inquiries
made of others by M. Maury, the results of his own experience, as well as
from my own observations, I am well convinced that the hypnagogic
hallucinations are directly the result of an increase in the amount of
blood circulating through the brain rather than to actual congestion as he
supposes. They therefore indicate the existence of a condition unfavorable
to sound sleep. In the chapter devoted to the consideration of wakefulness
the phenomena accompanying cerebral hyperæmia will be more fully
considered.
The theory which M. Maury proposes in order to account for the existence
of hypnagogic hallucinations further presupposes that as the power of the
attention immediately before sleep begins to be diminished, and the mind
cannot therefore voluntarily and logically arrange its thoughts, it
abandons itself to the imagination, and that thus fancies arise and
disappear unchecked by the other mental faculties. This absence of the
attention need not be of long duration, a second, or even a shorter period
being sufficient. Thus he lay down, and the attention which had been
fully aroused soon became weakened; images appeared, and these partially
reawakened the attention, and the current of his thoughts was resumed, to
be replaced again by hallucinations, and this continued till he was fully
asleep. As an example, he states that on the 30th of November, 1847, he
was reading aloud the _Voyage dans la Russie Méridionale_, by M. Hommaire
de Hell. He had just finished a line when he closed his eyes
instinctively. In this short instant of sleep he saw hypnagogically, but
with the rapidity of light, the figure of a man clothed in a brown robe,
and with a hood on his head like a monk. The appearance of this image
reminded him that he had shut his eyes and ceased reading. He immediately
opened his eyelids and resumed his book. The interruption was practically
nothing, for the person to whom he was reading did not perceive it.
M. Maury gives numerous examples of these hypnagogic hallucinations, all
tending to show that they are induced by a congested condition of the
cerebral vessels, and that thus, according to the views I have set forth
relative to the condition of the brain in sleep, they are not to be
regarded as precursors of that state, but of stupor.
In two very interesting cases of these hallucinations, which have come
under my notice, they were brought about by any cause which increased the
quantity of blood in the brain, or retarded the flow of blood from this
organ. Thus, a glass of champagne, or a few drops of laudanum, would
induce them, as also would the recumbent posture, with the head rather
low.
As showing how readily dreams can be excited by impressions made upon the
senses, M. Maury caused a series of experiments to be performed upon
himself when asleep, which afforded very satisfactory results, and which
are interesting in connection with the points already discussed in the
present chapter.
1st Experiment. He caused himself to be tickled with a feather on the lips
and inside of the nostrils. He dreamed that he was subjected to a horrible
punishment. A mask of pitch was applied to his face, and then torn roughly
off, taking with it the skin of his lips, nose, and face.
2d Experiment. A pair of tweezers was held at a little distance from his
ear, and struck with a pair of scissors. He dreamed that he heard the
ringing of bells; this was soon converted into the tocsin, and this
suggested the days of June, 1848.
3d Experiment. A bottle of eau de Cologne was held to his nose. He dreamed
that he was in a perfumer’s shop. This excited visions of the East, and he
dreamed that he was in Cairo in the shop of Jean Marie Farina. Many
surprising adventures occurred to him there, the details of which were
forgotten.
4th Experiment. A burning lucifer match was held close to his nostrils. He
dreamed that he was at sea (the wind was blowing in through the windows),
and that the magazine of the vessel blew up.
5th Experiment. He was slightly pinched on the nape of the neck. He
dreamed that a blister was applied, and this recalled the recollection of
a physician who had treated him in his infancy.
6th Experiment. A piece of red-hot iron was held close enough to him to
communicate a slight sensation of heat. He dreamed that robbers had got
into the house, and were forcing the inmates, by putting their feet to the
fire, to reveal where their money was. The idea of the robber suggested
that of the Duchess d’Abrantes, who he supposed had taken him for her
secretary, and in whose memoirs he had read some account of bandits.
7th Experiment. The word _parafagaramus_ was pronounced in his ear. He
understood nothing, and awoke with the recollection of a very vague dream.
The word _maman_ was next used many times. He dreamed of different
subjects, but heard a sound like the humming of bees. Several days after,
the experiment was repeated with the words _Azor_, _Castor_, _Léonore_. On
awaking, he recollected that he had heard the last two words, and had
attributed them to one of the persons who had conversed with him in his
dream.
Another experiment of the same kind showed like the others that it was the
sound of the word and not the idea it conveyed which was perceived by the
brain. Then the words _chandelle_, _haridelle_, were pronounced many times
in rapid succession in his ear. He awoke suddenly, saying to himself,
_c’est elle_. It was impossible for him to recall what idea he had
attached to this dream.
8th Experiment. A drop of water was allowed to fall on his forehead. He
dreamed that he was in Italy, that he was very warm, and that he was
drinking the wine of Orvieto.
9th Experiment. A light, surrounded with a piece of red paper, was
repeatedly placed before his eyes. He dreamed of a tempest and lightning,
which suggested the remembrance of a storm he had encountered in the
English Channel in going from Merlaix to Havre.
These observations are very instructive. They show conclusively that one
very important class of our dreams is due to our bodily sensations. I have
frequently performed analogous experiments on others, and had them
practiced on myself, and have rarely failed in obtaining decided results.
They strongly inculcate the truth of the conclusions arrived at in the
foregoing chapter, and they serve as important data in enabling us to
understand the division of the subject next to be considered.
In regard to the immediate cause of dreams the opinions of authors are
very diverse. The older writers ascribe them to the rise of vapors from
the stomach, to the visitation of demons, and other fanciful causes.
Bishop Bull[84] declares that he knows from his own experience that
dreams are to be ascribed “to the ministry of those invisible instruments
of God’s providence that guide and govern our affairs and concerns, viz.,
the angels of God;” and Bishop Ken held a similar view.
It would neither be possible nor profitable to refer at greater length to
views which positive physiology has overturned. Observation and experiment
have aided us greatly in arriving at definite conclusions on this subject,
and the instances quoted on page 30 of this treatise, even if standing
alone uncontradicted, would go far toward guiding us in the right path. On
page 37 I have referred to the case of a man who, some time after
receiving a severe injury of the head by which a considerable portion of
the skull was lost, came under my professional care. Standing by his
bedside one evening, just after he had gone to sleep, I observed the scalp
slightly rise from the chasm in which it was deeply depressed. I was sure
he was going to awake, but he did not, and very soon he became restless
and agitated, while continuing to sleep. Presently he began to talk, and
it was evident that he was dreaming. In a few minutes the scalp sank down
to its ordinary level when he was asleep, and he became quiet. I called
his wife’s attention to the circumstance, and desired her to observe this
condition thereafter when he slept. She subsequently informed me that she
could always tell when he was dreaming from the appearance of the scalp.
My opinion, therefore, is that dreams are directly caused by an increased
activity of the cerebral circulation over that which exists in profound
sleep. This activity is probably sometimes local and at others general,
and never equals that which prevails in the condition of wakefulness, when
the functions of the brain are at their maximum of energy. This view is
further supported by a consideration of the state of the brain in sleep
and wakefulness, the condition of dreaming being, in a measure, an
intermediate one. Illustrations of the effects produced by a notable
increase in the quantity of blood circulating through the brain will be
given in the chapter on wakefulness. All of these, it will be perceived,
have a direct bearing on the question now under consideration.
CHAPTER VI.
MORBID DREAMS.
Morbid or pathological dreams are divided by Macario[85] into three
classes: the prodromic, or those which precede diseases; the symptomatic,
or those which occur in the course of diseases; and the essential, or
those which constitute the main features of diseases. As this
classification is natural and simple, I propose to follow it in the
remarks I shall have to make on the subject.
PRODROMIC DREAMS.--There appears to be no doubt that diseases are
sometimes preceded by dreams which indicate with more or less exactitude
the character of the approaching morbid condition. Many instances of the
kind which have been reported--especially by the earlier authors--are,
however, in all probability merely coincidences; and in others the
relation between the character of the dream and that of the disease is by
no means clear.
Many cases of dreams indicating the nature of a malady which had not yet
developed itself are referred to by Macario.[86] The instance of Galen’s
patient, who dreamed that his leg had become converted into stone, and who
was soon afterward paralyzed in that member, has already been cited.
The learned Conrad Gesner dreamed that he was bitten in the left side by a
venomous serpent. In a short time a severe carbuncle appeared on the
identical spot, and death ensued in five days.
M. Teste, formerly minister of justice and then of public works under
Louis Philippe, and who finally died in the Conciergerie, dreamed three
days before his death that he had had an attack of apoplexy. Three days
afterward he died suddenly of that disease.
A young woman saw in a dream objects apparently confused and dim as
through a thin cloud, and was immediately thereafter attacked with
amblyopia, and threatened with loss of sight.
A woman, who had been under the care of M. Macario, dreamed at about the
period of her menstrual flow that she spoke to a man who could not answer
her, for the reason that he was dumb. On awaking she discovered that she
had lost her voice.
Macario himself dreamed one night that he had a severe pain in his throat.
On awaking he felt very well; but a few hours subsequently was attacked
with severe tonsillitis.
Arnold, of Villanova, dreamed that a black cat bit him in the side. The
next day a carbuncle appeared on the part bitten.
Dr. Forbes Winslow[87] gives several similar instances. A patient had, for
several weeks before an attack of apoplexy, a series of frightful dreams,
in one of which he imagined he was being scalped by Indians. Others dreamt
of falling down precipices, and of being torn to pieces by wild beasts.
One gentleman dreamed that his house was in flames, and that he was
gradually being consumed to a cinder. This occurred a few days before an
attack of inflammation of the brain. A person, prior to an attack of
epilepsy, dreamt that he was severely lacerated by a tiger; and another,
just before a seizure, dreamt that he was attacked by murderers, and that
they were knocking out his brains with a hammer.
A barrister, for several years before an attack of cerebral paralysis, was
in the habit of awaking from sleep in a condition of great alarm and
terror without being able to explain the reason for his apprehension. Dr.
Beddoes attended a patient whose first fit succeeded a dream of being
crushed by an avalanche.
Gratiolet[88] cites additional examples. Thus, Roger d’Oxteryn, Knight of
the Company of Douglas, went to bed in good health. Toward the middle of
the night, he saw in a dream a man affected with the plague and entirely
naked, who attacked him with fury, threw him to the ground after a severe
contest, and, holding him between his thighs, vomited into his mouth.
Three days afterward he was seized with the plague and died. He also
alludes to a case detailed by Gunther, in which a woman dreamt that she
was being flogged with a whip, and on awaking found that she had marks on
her body resembling the scars made by the lash.
The existence of diseases of the heart and larger vessels is often
revealed by frightful dreams when there is no other evidence of their
presence. Macario states that a young lady was under his care in whom
violent palpitations of the heart were preceded by painful dreams. She
subsequently died of disease of the heart.
Moreau (de la Sarthe),[89] in a very elaborate treatise on dreams, relates
the case of a French nobleman, whom he had attended during several months
for threatened chronic pericarditis, and who was at first tormented every
night by painful and frightful dreams. These dreams, attracting attention,
gave the earliest indication of the real condition, and excited fears as
to the result, which were soon verified.
He cites another case in illustration of the fact that periodical
hemorrhages are sometimes preceded by morbid dreams. A physician had, in
his youth, been subject to periodical hemorrhages, but without dreams or
other trouble during sleep. As he advanced in years, the hemorrhages were
not so frequent, but were always preceded by a condition of general
irritation, characterized during wakefulness by heat of skin and frequency
of the pulse, and during sleep by painful dreams. These dreams almost
always related to violent actions, such as giving and receiving heavy
blows, walking on a volcano, or being precipitated into lakes of fire.
Many cases of insanity being preceded by frightful dreams are on record.
Falret,[90] in calling attention to the remarkable analogy which exists
between mental alienation and dreams, says that it is an incontestable
fact that insanity is often preceded by significant dreams, and that these
constitute the whole essence of the disorder by becoming firmly fixed in
the patient’s mind. Thus, he relates that Odier of Geneva was consulted in
1778 by a lady, who, during the night preceding the outbreak of her
insanity, dreamed that her step-mother approached her with a dagger in
order to kill her. This dream made so strong an impression upon her that
she ultimately accredited it as true, and thus became the victim of a
delusion which rendered her a lunatic. He declares that numerous similar
instances have come under his observation, and refers to the case of a
young lady, subject to periodical attacks of mental derangement, whose
paroxysms are always preceded by notable dreams.
Morel[91] affirms that many patients before becoming completely insane
have frightful dreams, which they regard as evidences that they are about
to lose their reason. Sometimes they are afraid to go to sleep on account
of the terrifying apparitions which then visit them.
The following cases, related by Dr. Forbes Winslow,[92] are interesting in
this connection:
“A gentleman, who had previously manifested no appreciable symptoms of
mental disorder, or even of disturbed and anxious thought, retired to bed
apparently in a sane state of mind. Upon arising in the morning, to the
intense terror of his wife, he was found to have lost his senses! He
exhibited his insanity by asserting that he was going to be tried for an
offense which he could not clearly define, and of the nature of which he
had no right conception. He declared that the officers of justice were in
hot pursuit of him,--in fact, he maintained that they were actually in the
house. He begged and implored his wife to protect him. He walked about the
bed-room in a state of great agitation, apprehension, and alarm, stamping
his feet, and wringing his hands in the wildest agony of despair. Upon
inquiring into the history of the case, his wife said that she had not
observed any symptoms that excited her suspicions as to the state of her
husband’s mind, but upon being question
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