referendi, subjungam: Puella xviii. annorum cachectica, et cui nondum
menses fluxerant, indeque nonnihil asthmatica, ex narrationibus,
crebrioribus servæ seu famulæ, primum imaginationem Incubi concipit, cum
ab illa sæpius audivisset, se quavis nocte Incubo corripi, et istud mali
ab alio concitari. Jam utut hæc ipsa dimissa fuerit, illa tamen mox ab
hujus discessu Incubo corripi cepit; nempe omni nocte præcise horâ secundâ
incipit quiritare, hinc mox sensu et motu privata jacet, donec successivè
ad se redeat, quo tempore sudore madet, et hinc inde in corpore, maculas
magnas rubras, præsertim in femoris parte carnosa observat. Hæc quavis
nocte eodem præcisè tempore redeunt. Ergo suspicabar Incubum esse revera
convulsivum in subjecto hypochondriaco cachectico. Dedi Tartari Emetici,
g. iij. qui parum operabatur, et hinc quovis mane de Pulvere Cachectico
seu Croco Martis Aperitivo largam dosin prohibendo acida. Successus fuit,
ut post aliquot dies noctesque, Incubus tardiùs affligeret, hora tertia,
hinc quarta, tandem quinta matutina, tandem per biduum, penitus deficeret,
quo transacto hora quinta matutina malum redit, sed absque maculis.
Propino Vomitorium liquidum, cujus usu cum copiosa mucosa rejecisset, non
rediit Incubus. Suasi ut Elixyr Proprietatis imposterum continuaret,
certus, modò primæ viæ a cruditatibus acido pituitosis essent liberæ, et
hinc menses comparerent, eam pancraticè valituram._”
To those to whom the disease is habitual, there remains after the paroxysm
a sense of lassitude, heaviness, drowsiness, and a continued
predisposition to the affection; so that if they indulge in sleep, they
are almost certain of a return of the symptoms. It is not easy to describe
this state, but the patient is very sensible of it, and every one who is
subject to this affection, can easily tell when the predisposition to it
exists.
This state of predisposition I have often experienced during the day, but
this only happens when the disease has arrived at a very great height. It
is attended with a sensation of something like a weight and great
uneasiness about the heart, requiring often a sudden and full inspiration
of the lungs, and obliging me to rise up and walk about a little, in order
to be clear of it. If in this state, I sit down to read or write, the
propensity to sleep is so great that in the space of a few seconds, after
having directed the whole attention of the mind to the object on which I
chance to be employed, I find my thoughts involuntarily carried away to
distant scenes, and that I am in reality dreaming, from which state I am
only roused by a sense of something like suffocation, and the unpleasant
sensation before mentioned about the heart. This is relieved for the
moment by a sudden and strong inspiration; but if the sedentary employment
be continued, it quickly returns. If in this state I yield to the strong
inclination to sleep, a severe paroxysm of Incubus is the inevitable
consequence, and that in the course of a very few minutes. When this
peculiar sensation about the heart occurs in bed, there is no recourse
left but rising instantly, and walking it off, or having recourse to such
medicines, if they are at hand, as experience has taught me are
efficacious in the removal of it.
These are I believe the most common phenomena attending Night-Mare. I must
beg leave, however, to remind the reader, that there are various degrees
of this affection, as well as of the predisposition to it; all of which
more or less disturb the rest, and derange the system. All unpleasant
dreams may be considered as certain modifications of this peculiar
affection; such as falling down precipices, or standing on their brink, or
being in the midst of a torrent, or in imminent danger of our lives. If
these ideas continue long, they generally produce a degree of
consciousness that we are asleep, which is succeeded by an attempt to
evade the danger by waking ourselves, which constitutes real Night-Mare.
There is, however, another kind, which differs a little from this I have
been describing, but is nevertheless to be considered as a modification of
Night-Mare, arising from the same cause, and requiring the same remedies;
for which reason I shall include it in my History of that disease. I mean
that undescribable terror which some persons feel in their sleep, and
which frequently obliges them to vociferate loudly, and generally to start
with violence, or sometimes even to jump out of bed. This terror is often,
perhaps mostly, accompanied by some really terrific dream. This is not
always the case, however, and when it does happen, the dream is rather to
be considered as the effect of the terror, than the cause of it. I have
frequently found this terror to be connected with some object, not at all
in itself terrific; as for instance, a cat or a dog, or sometimes a little
child which I had been contemplating in my dream for some time without any
dread or terror, has all at once become an object of the utmost horror and
alarm, and that without at all changing its appearance or attitude. A
sudden panic has struck me with a degree of terror, which I am convinced
nothing on earth could produce in me when awake; and which obliges me to
vociferate with uncommon vehemence, and to start with so much violence as
generally to wake myself immediately, and frequently great part of the
family beside. It would be impossible by any words, to convey an adequate
idea of the terror felt during this affection: the patient continues to
feel it for several minutes after he is awake; at least it requires some
little time for even a strong mind to recover its tranquillity. I have
always observed in my own case, as well as in all those I have had the
opportunity of investigating, that this kind of affection is universally
accompanied with a sensation called shivering; not precisely of that kind
which accompanies the paroxysm of ague, but that momentary sensation of
shivering which people are apt to feel on hearing any tale of horror
related, or frequently indeed, without any evident cause whatever. It is a
vulgar opinion, that this shivering takes place whenever any one is
walking over the future grave of the person who feels it. This kind of
shivering is, at all times, accompanied with some degree of horror, and
that has probably been the reason of the superstitious opinion above
mentioned. Hence also the common expression, on hearing a tale of horror,
that _it makes the blood run cold_; which is precisely the sensation of
the person, both in the dreams themselves which we are speaking of, and
for some little time after waking out of them. This sensation is always
referred to the spine, and appears to descend from the neck to the loins.
The cause of it is not very easy to explain; it evidently belongs to that
class of sensations and affections which we call nervous, and appears in
this case to be the immediate cause of that terror which invades us in
sleep, by inducing some idea of great horror.
Amongst all the subjects of terror which infest the human mind, there is
none so powerful as the idea, which is generally imbibed at a very early
period of life, respecting ghosts and supernatural appearances; and there
are comparatively few persons who, when alone and in the dark, are
perfectly free from them. In sleep, however, we are all much more timid
than when awake. I believe every person’s experience coincides in this
opinion: hence it arises, that the idea of ghosts and spectres being the
idea which inspires us with the greatest terror, is that which most
readily and frequently presents itself to the mind, when the nervous
system is suddenly agitated during sleep; a state when all objects of fear
act with increased force. Whatever may be the cause which induces this
kind of shivering during sleep, the shivering itself appears to me
evidently to be the immediate cause of the terror, and the accompanying
terrific dream; and this I conceive to happen from association; for as
this shivering is the kind of involuntary sensation we feel when suddenly
alarmed, or even when we hear or read a tale of terror, the feeling itself
becomes so associated with terror, as always to recal to the mind, even in
sleep, the idea of it; the sensation being the same as if the nerves had
actually received some terrific impression; and as the imagination has
full play when asleep, it is seldom long in furnishing the terrific
object.
I have known these dreams to be succeeded by an hysterical affection, of
involuntary laughing and crying; and they are, I believe, in all cases
attended with a great degree of nervous irritability.
It will sometimes happen in this case, as in the preceding, that the
patient does not awake from his dream, notwithstanding that his
vociferations have been loud enough to wake all those who may sleep near
him. When this happens he seldom or never has any recollection of his
terror, and feels greatly surprised when told of the alarm he had given to
others. The moment the shivering which produced the terror has ceased,
this likewise ceases; and seldom leaves in the mind, any trace of its
having existed: in this respect it differs greatly from the Night-Mare, in
some others it appears to have some considerable affinity to that
affection.
It is not uncommon for persons affected with these terrific dreams to leap
out of bed, and attempt to escape from some imaginary danger by flight.
Many instances have occurred of persons jumping immediately out of a high
window under these circumstances: the same accident very lately occurred
to a youth in this metropolis.
There are several other accidents to which our sleep is liable, but as
they differ in their nature considerably from Night-Mare, we shall not
here take any notice of them.
I shall now speak of the persons who are subject to Night-Mare, before
entering into an investigation of its causes.
This affection may at some time or other occur to any person whatever, as
it will for the most part be found to be the constant attendant upon
indigestion: now the most healthy person in the world will sometimes meet
with food which his stomach will not digest, and if he goes to sleep
whilst such food is remaining in the stomach, or in the superior portion
of the alimentary canal, he will certainly be affected with Night-Mare, to
a greater or less degree. But a peculiar habit of body is necessary to
render a person subject to it, so that it can become habitual. Many
persons begin to feel its effects in very early youth; these are generally
of a contemplative disposition, and of a peculiar temperament, which
renders them liable to hypochondriasis and nervous diseases. To these
persons the Night-Mare often becomes habitual. All who follow sedentary
employments, or whose avocations keep them mostly in doors, more
especially literary characters, and all studious persons, are the victims
of these affections. Those likewise, who, although they do not want for
air and exercise, yet are accustomed to a coarse and unwholesome diet;
hence sailors are, of all classes of men, the most subject to Night-Mare
and terrific dreams. All hypochondriacs, and frequently pregnant women,
are amongst the subjects of these affections.
It occasionally accompanies fever and other acute diseases. I remember one
patient to whom it became extremely troublesome in the last stage of
consumption, who had never before in her life been affected by it. Sylvius
Deleboe, who has recorded the _history_ of an epidemic disease, which
raged in the city of Leyden, in the year 1669, mentions the Incubus as a
very common affection in it, with which he was himself afflicted to a
great degree. He describes it as accompanied with an unusual degree of
somnolency, and making its attack on the accession of the febrile
paroxysm. Perhaps it was something of this kind, which Cœlius Aurelianus
asserts to have been epidemic at Rome. Sylvius relates that the lethargy,
or propensity to sleep, was so great during the febrile paroxysm, and
accompanied with so unpleasant a sensation, even when Night-Mare did not
come on, that he thought proper to order himself, as well as his patients,
to be kept awake by the attendants. He describes it thus: “_Non tantum cum
Incubo, sed absque ipso gravis fuit ægris multis Somnus profundus, et
insomniis multifariis molestus_.” In another place, “_Nec tantum sola
difficili respiratione laborarunt multi, verum etiam Incubo nonnulli, et
inter ipsos ego quoque; qui cum paroxysmis febrilibus repetens atque
somnolentiam simul excitans, fuit mihi valdè molestus, donec ipsum
agnoscens rogarem adstantes, ut tamdiu somnum in quem tam valde
propendebam, interturbarent ac impedirent, donec paroxysmo declinante in
somnum suavem ac commodum inciderem absque omni incubo_.” Sylvii Praxeos.
Med. Tract. x.
It sometimes appears in very early life, in which case it generally sticks
close to the patient, almost all his days. In some, however, such a
change in the constitution takes place at puberty as destroys altogether
that predisposition to this affection, which existed in early life.
Females appear much less subject to it, than males, though by no means
exempt. Of these, virgins and pregnant women are more particularly liable
to its attacks, as well as all those who are much visited by hysterical
affections, constipation, and flatulency. It is sometimes also found to
accompany the _chlorosis_ or green sickness. On the whole, however, it is
of comparatively rare occurrence amongst females.
Neither is this disease very common in advanced life, unless where
corpulency, or a tendency to lethargy exists. In those cases however where
it does occur, it is more to be dreaded than in youth or middle age. It is
no unfrequent attendant on asthmatic persons.
The opinions of medical men with respect to the immediate cause of this
disease, or what by them is termed its proximate cause, have been various
and discordant, as generally happens in all obscure investigations. In all
probability every one of them are wrong, so that it can be of little
utility to inquire into them. There is however one idea, which seems to be
more universally adopted than any other, and which deserves notice; it is,
that this affection is produced by a cause purely mechanical, and
depending on the position of the body. Some plausible theories have been
formed on this supposition, by assigning to the different thoracic and
abdominal viscera, certain relative positions which would occasion a
temporary pressure upon the organs of respiration, or upon some branch of
the intercostal nerves. With respect to this mechanical pressure, arising
from any imagined position of the patient, what I have already said on
that score, renders this hypothesis vain, for there is no position in
which it is possible for a person to fall asleep, in which I have not been
attacked by Night-Mare. Neither is there any more dependence to be placed
on the generally received opinion, of the disease being induced by a full
stomach. It may naturally be supposed, that any person labouring under
this affection to the degree which I have stated, although I have as yet
given a very feeble idea of its extent, would take every possible
precaution to keep clear of the causes, which were so generally believed
to have produced it. I religiously abstained, for many years from eating
any thing after dinner, and took dinner also at as early an hour as two
o’clock. It was during this period that I suffered most from the disease.
I think I may safely assert, that for more than twenty years, I have never
once, to the best of my recollection, fallen asleep on my back, or ever
found myself in that position on waking. When night after night has been
rendered miserable by this enemy of repose, I have had recourse to every
expedient which deep reflection could suggest. The perpendicular position
of the body, I have found by experience to be the worst in which a
paroxysm of Night-Mare can be borne. The difficulty of respiration, and
all the other symptoms are greatly aggravated, and an additional one is
felt, which greatly increases the sufferings of the patient; it is a
perpetual dread of falling, which appears inevitable, and which prevents
the patient from struggling so much as he would do if in a horizontal
position. Next to this is the position of sleeping with the body bent
forwards, and the head reclining with the face downwards on a table: in
this last position, the difficulty of inflating the lungs is extreme. I
have never been able to discover that any great difference arose between
sleeping on the right or left side. I have always considered it as a
matter of indifference. Although it is possible to render the paroxysm of
Night-Mare more tolerable by any particular position of the body, yet I am
well assured that no position will secure a person from its attacks, to
whom it has once become habitual. I slept for some time in an easy chair,
and found the disease greatly aggravated by it.
There must however be some reason for the universal opinion that it always
attacks persons lying on the back. I was for a long time of opinion
myself, that I was always lying in that position when the paroxysm came
on, but as the disease gained strength, and the paroxysms hung more
pertinaciously upon me, I became more perfectly awake, so as to be able to
discover more accurately the position in which I was lying, and I found
that little faith was to be given to the sensations that may occur during
Night-Mare, as they are the most deceitful of all evidences. It appears to
be one of the symptoms almost inseparable from the disease, that the
patient should appear to himself to be kept down upon the back by some
external force. This sensation I have almost always felt, even when I have
had the evidence of other people, as well as my own conviction when awake,
that I was in reality lying on the side. I cannot help suspecting that
many others have been deceived in a similar manner, and thus made to
believe, that they never had the Night-Mare except when sleeping on their
backs. There is also another sensation which is very apt to deceive the
patient, that is, on the paroxysm going off, and the moment of his
recovering the power of volition, a great confusion of ideas always takes
place, and a person to whom the Night-Mare is not very familiar, generally
imagines that he has recovered himself by some effort of his own,
frequently by turning from his back to his side, sometimes by sitting
upright in bed. These things are all extremely fallacious; there is no
trusting to the senses during a paroxysm of Incubus; nothing short of the
evidence of another person ought to satisfy the patient. I have often been
thoroughly convinced in my own mind that I had succeeded in throwing the
bed-clothes off my breast, and by that means gained relief, and not
unfrequently, that I had risen from bed, and opened the window to admit
air; yet both these ideas have been proved to be incorrect. I have often
felt very certain that my right arm was out of bed, and that I had moved
it about; but on waking thoroughly, I have found it under the bed-clothes,
and in a situation in which it could not have been moved. I cannot help
thinking then, that the universal idea of its attacking persons
exclusively lying on the back, is founded on an error, arising out of the
ordinary sensations of the patients themselves, who have always that idea,
let them be in what position they will. Several persons, subject to
habitual Night-Mare, have become convinced of the truth of this
observation, which I had made to them, after attending more closely to
their real situation during the continuance of, and immediately after the
paroxysm. I have also convinced one or two medical friends, who were
extremely sceptical on that point, that it would attack me in any
position, by going to sleep before them, on a chair, or sofa, when my own
feelings have indicated the certainty of attack, if I should indulge for a
few moments the propensity I felt to sleep.
Neither is it necessary for the stomach to be filled with food, in order
to produce Night-Mare, as is evident from what I have stated above with
respect to the abstinence I observed during the period in which I suffered
most from this affection. Experience has taught me that I may eat heartily
of some kinds of food, just before going to bed, with impunity; whilst the
smallest quantity of some other will inevitably bring on the disease, in
spite of all the precautions that can be taken.
Thus then we must give up every explanation of the phenomena which occur
in this disease, founded upon principles purely mechanical, however
plausible they may appear. Neither is the opinion of Darwin more correct,
that the Night-Mare is nothing more than a consciousness of the suspension
of the power of volition, and a desire to recover that power. If so, it
would differ little from sleep itself; or, however fatiguing it might be
to the mind, it could not occasion any derangement in the functions. The
breathing and the circulation would go on without any interruption, as in
sleep; nor would there be any thing that could produce the sense of
oppression on the breast. Darwin was well aware of this difficulty, and
therefore chose rather to contradict the generally received opinion of
oppression and difficulty of respiration. There is no doubt whatever of
the difficulty of breathing, which any one may assure himself of, if he
could have the opportunity of seeing a patient during the paroxysm of
Night-Mare. I have taken considerable pains to assure myself of this
circumstance from the evidence of other persons.
I must confess I have not hitherto been able to find any satisfactory
explanation of the phenomena which take place during Night-Mare. The
following observations which I have been able to make on the paroxysm
itself, and on the more immediate causes which give rise to it, may
possibly direct some happier genius to a more correct idea of its nature.
1st. I have frequently experienced that this affection may occur in very
profound sleep, without breaking or disturbing that sleep, any farther
than to produce a dream, the memory of which will remain after waking, in
the same manner as that of any other impressive dream. Thus I have
frequently dreamed that I had Night-Mare; supposing myself to be in a
place, and under circumstances very different to those in which I really
was. Under these circumstances I have never become conscious of the real
situation in which I was, but on waking, remembered very well that I had
been dreaming of labouring under Night-Mare. From this circumstance I
conclude, that the Night-Mare is not, as Dr. Darwin insinuates, a state of
imperfect sleep, but an absolute disease, which may occur, and go through
its regular stages, whilst the patient continues to be, to all intents and
purposes, in a natural sleep. There is no doubt but the disease, in this
case, is much slighter than ordinary, although the impression made upon
the mind may be very strong.
2nd. It happens still more frequently, that the patient is in a state
apparently between sleeping and waking, when the paroxysm takes place;
which has given rise to the belief, in many persons, that it came on
while awake. I have often heard it described by others, (and have felt it
myself) as a sense of weight, first upon the feet, and progressively
advancing towards the breast, until the paroxysm becomes complete. In the
beginning of this state of things, it appears to the patient that he might
easily, if he would, move himself, and shake off the incumbent weight. He
does not feel at all aware at that moment, of the suspension of the power
of volition; nor does he feel any inconvenience from that circumstance
until he begins to experience a necessity of exerting that power, in order
to carry on the function of respiration. It is not until the involuntary
action of the muscles concerned in respiration, in some measure ceases,
that the patient perceives that he is absolutely labouring under
Night-Mare.
I have paid very close attention to this circumstance, and have been
repeatedly convinced, that whenever the disease attacked in this manner,
I was always asleep at the commencement of the paroxysm, and that as soon
as I became conscious of my situation, or in other words, _awake_, the
power of volition was completely suspended, although very little
inconvenience arose from it; for, on making the attempt to move, which
appears very easy to do, I have always felt the paroxysm of Night-Mare to
be completely formed, and the difficulty of respiration, which before did
not exist, immediately to come on, and with it all the anxiety and
distress which characterize this disease.
From this I infer, that a suspension of volition always exists during a
paroxysm of Incubus, but that this is not alone sufficient to constitute a
complete Night-Mare, even when attended with a consciousness of our
situation. It is likewise necessary that the involuntary action of the
respiratory organs should experience some interruption, and I am disposed
to think that the circulation through the lungs, and the action of the
heart itself, partakes of this interruption. I conceive also, that the
difficulty of inflating the lungs is always increased in proportion as the
patient becomes more awake.