ON THE INCUBUS, OR NIGHT-MARE.

J. M‘Creery, Printer,
Black Horse Court, London.

A

TREATISE

ON

THE INCUBUS,

OR

Night-Mare,

DISTURBED SLEEP, TERRIFIC DREAMS,

AND

NOCTURNAL VISIONS.

WITH THE MEANS OF REMOVING THESE DISTRESSING
COMPLAINTS.

By JOHN WALLER,
SURGEON OF THE ROYAL NAVY.

LONDON:
PRINTED FOR E. COX AND SON, ST. THOMAS’S STREET,
BOROUGH.

1816.

INTRODUCTION.

The enjoyment of comfortable and undisturbed sleep, is certainly to be ranked amongst the greatest blessings which heaven has bestowed on mankind; and it may be considered as one of the best criterions of a person enjoying perfect health. On the contrary, any disturbance which occurs in the enjoyment of this invaluable blessing, may be considered a decisive proof of some derangement existing in the animal economy, and a consequent deviation from the standard of health. Indeed it is astonishing how slight a deviation from that standard may be perceived, by paying attention to the circumstance of our sleep and dreams. This may be more clearly demonstrated by attending carefully to the state of persons on the approach of any epidemic fever or other epidemic disease, and indeed of every kind of fever, as I have repeatedly witnessed; when no other signs of a deviation from health could be perceived, the patient has complained of disturbed rest and frightful dreams, with Night-Mare, &c. Hence the dread which the vulgar, in all ages and countries, have had of what they call bad dreams; experience having proved to them, that persons, previously to being attacked with some serious or fatal malady, had been visited with these kind of dreams. For this reason they always dread some impending calamity either to themselves or others, whenever they occur; and, so far as relates to themselves, often not without reason. Frightful dreams, however, though frequently the forerunners of dangerous and fatal diseases, will yet often occur when the disturbance of the system is comparatively trifling, as they will generally be found to accompany every derangement of the digestive organs, particularly of the stomach, of the superior portion of the intestinal canal, and of the biliary system. Children, whose digestive organs are peculiarly liable to derangement, are also very frequently the subjects of frightful dreams, and partial Night-Mares; which are frequently distressing enough to them. They are still more so to grown up people, as they generally arise from a more serious derangement of the system. Those who are subject to them will agree with me in opinion, that they are by no means to be ranked amongst the lesser calamities to which our nature is liable.

There are many persons in the world to whom it is no uncommon occurrence, to rise from their bed in the morning more wearied and exhausted, both in mind and body, than when they retired to it the evening before: to whom sleep is frequently an object of terror rather than comfort, and who seek in vain for relief from the means usually recommended by Physicians. To such persons I dedicate this little work; for their information I have laid down, in as clear terms as the subject will admit, the history of those diseases, which, by depriving us of the benefit of sleep, and driving rest from our couch, often render life itself miserable, and lay the foundation of formidable, and sometimes of fatal diseases. Amongst those affections which thus break in upon our repose, the most formidable and the most frequent is the disease called Night-Mare; the history of which, with its various modifications, I have endeavoured to give with as much accuracy as possible, and have attempted also to investigate its nature and immediate causes, as well as to point out the best mode of obtaining relief. Very little assistance could be obtained in this undertaking, from the writings of modern Physicians, who have paid little or no attention to it: those of the sixteenth and seventeenth centuries, seem to have well understood both its causes and cure, but differed much amongst themselves respecting its nature, as will ever be the case when we attempt to reason on any subject which is above our comprehension. I have availed myself of all the light which these illustrious men could throw upon the subject, which is not a little; but my principal information respecting it has arisen from a personal acquaintance with the disease itself, for a long series of years, having been a victim to it from my earliest infancy. I have never met with any person who has suffered to so great an extent from this affection, or to whom it was become so habitual. To eradicate thoroughly a disease so deeply rooted and of so long duration, cannot be expected: but I have so far succeeded as to bring it under great control, and to keep myself free from its attacks for several months together; or indeed scarcely ever to be disturbed by it at all, but when I have deviated from those rules which experience has proved to be sufficient to secure me from all danger of it.

The various kinds of disturbed sleep taken notice of in this little work, are all so many modifications of Night-Mare, and may be all remedied by observing the rules here laid down, as they will be found to originate from one or other of the causes here specified. The regimen and treatment I have recommended are directed to the root of the disease, that is, to the hypochondriac or hysteric temperament; for Night-Mare, disturbed sleep, terrific dreams, &c. may be considered only as symptoms of great nervous derangement, or hypochondriasis, and are a sure sign that this disease exists to a great extent. Thus, while the patient is seeking, by the means recommended, to get rid of his Night-Mare, he will find his general health improving, and the digestive organs recovering their proper tone.

THE INCUBUS, &c.

This disease, vulgarly called Night-Mare, was observed and described by physicians and other writers at a very early period. It was called by the Greeks, εφιαλτης, and by the Romans, Incubus, both of which names are expressive of the sensation of weight and oppression felt by the persons labouring under it, and which conveys to them the idea of some living being having taken its position on the breast, inspiring terror, and impeding respiration and all voluntary motion. It is not very surprising that persons labouring under this extraordinary affection, should ascribe it to the agency of some dæmon, or evil spirit; and we accordingly find that this idea of its immediate cause has generally prevailed in all ages and countries. Its real nature has never been satisfactorily explained, nor has it by any means met with that attention from modern physicians which it merits: indeed it scarcely seems to be considered by them as a disease, or to deserve at all the attention of a physician. Those, however, who labour under this affection to any great degree, can bear testimony to the distress and alarm which it occasions; in many cases rendering the approach of night a cause of terror, and life itself miserable, from the dread of untimely suffocation. The little attention paid to this disease by medical men, has left the subjects of it without a remedy, and almost without hope. Its nature and its cause have been altogether misunderstood by those who have lately given any opinion upon it. It appears a general opinion that it only happens to persons lying upon the back, and who have eaten large suppers; the causes of it have consequently been traced to mechanical pressure upon the lungs, arising from a full stomach; and a change of position, together with the avoiding eating any supper, has been thought all that was necessary to prevent its attack. To those, however, who are unfortunately afflicted with it to any degree, it is well known by experience, that no change of position, or abstinence, will secure them from the attacks of this formidable disturber of the night. As I have so long been an unfortunate victim to this enemy of repose, and have suffered more from its repeated attacks than any other person I have ever met with, I hope to be able to throw some light on the nature of this affection, and to point out some mode of relief to the unfortunate victims of it.

The late Dr. Darwin, who had an admirable talent for explaining the phenomena of animal life in general, is of opinion, that this affection is nothing more than sleeping too sound; in which situation of things the power of volition, or command over the muscles of voluntary motion, is too completely suspended; and that the efforts of the patient to recover this power, constitute the disease we call Night-Mare. In order to reconcile this hypothesis with the real state of things, he is obliged to have recourse to a method not unusual amongst theoretic philosophers, both in medicine and other sciences—that is, when the hypothesis does not exactly apply to the phenomenon to be explained by it, to twist the phenomenon itself into such a shape as will make it fit, rather than give up a favourite hypothesis. Now, in order to mould the Night-Mare into the proper form, to make this hypothesis apply to it, he asserts, first, that it only attacks persons when very sound asleep; and secondly, that there cannot exist any difficulty of breathing, since the mere suspension of volition will not produce any, the respiration going on as well asleep as awake; so that he thinks there must needs be some error in this part of the account. Any person, however, that has experienced a paroxysm of Night-Mare, will be disposed rather to give up Dr. Darwin’s hypothesis than to mistrust his own feelings as to the difficulty of breathing, which is far the most terrific and painful of any of the symptoms. The dread of suffocation, arising from the inability of inflating the lungs, is so great, that the person, who for the first time in his life is attacked by this “worst phantom of the night,” generally imagines that he has very narrowly escaped death, and that a few seconds more of the complaint would have inevitably proved fatal. This disease, although neglected by modern physicians, was well described and understood by those of the seventeenth century, as well as by the Greeks and Romans.[1] There are few affections more universally felt by all classes of society, yet it is seldom at present considered of sufficient consequence to require medical advice. To those nevertheless who, from sedentary habits, and depraved digestion, are the most frequent subjects of it, it is a source of great anxiety and misery, breaking in upon their repose, and filling the mind with constant alarms for more serious consequences, “making night hideous,” and rendering the couch, which is to others the sweet refuge from all the cares of life, to them an object of dread and terror. To such persons, any alleviation of their sufferings will be considered an act of philanthropy; as they are now in general only deterred from applying to the practitioners of medicine for relief, from the idea that their case is out of the reach of medicine.

It is a very well known fact, however, that this affection is by no means free from danger. I have known one instance in which a paroxysm of it certainly proved fatal, and I have heard of several others. I do not doubt indeed but that this happens oftener than is suspected, where persons have been found dead in their beds, who had retired to rest in apparent health. I do not know that any late writer has observed a fatal case of Night-Mare, but we find a circumstance recorded by Cœlius Aurelianus, who is supposed to have lived a short time before Galen, which, if true, is very remarkable; and I know no reason why it should be doubted. Yet I am aware that in the age in which we live, it is a common practice, not merely to doubt, but to contradict every fact recorded by ancient writers, which, if admitted, would militate against any received theory. Cœlius Aurelianus, however, informs us, upon the authority of Silimachus, a follower of Hippocrates, that this affection was once epidemic at Rome, and that a great number of persons in that city died of it.[2]

A young man, of sober habits, about thirty years of age, by trade a carpenter, had been all his life subject to severe attacks of Night-Mare. During the paroxysm he frequently struggled violently, and vociferated loudly. Being at Norwich for some business, which detained him there several weeks, he one night retired to bed in apparent good health; whether he had eaten supper, or what he had taken previously to going to bed, or during the day, I cannot now remember. In the night, or towards morning, he was heard by some of the family in the house where he lodged to vociferate and groan as he had been accustomed to do during the paroxysms of Night-Mare; but as he was, after no great length of time, perfectly quiet, no person went to his assistance. In the morning, however, it was soon observed that he did not, as usual, make his appearance, and on some person going into his room, he was found dead, having thrown himself by his exertions and struggles out of bed, with his feet, however, still entangled among the bed-clothes. This patient, and the circumstances attending his death, were very well known to me, and I have not the least doubt that it was Night-Mare which proved fatal to him. A similar case has been related to me by a person deserving of credit, and I do not doubt but they are of more frequent occurrence than is generally supposed. It may appear surprising to some, that a person should struggle with so much violence as to throw himself out of bed, and yet not shake off the Night-Mare, since, in general, it is sufficient to call a person by his name, and he will recover. This is indeed true in common cases, and in every case it is of much more service than any exertions which the patient himself can make. I once at sea, in a paroxysm of Night-Mare, threw myself out of my cot, and it nearly cost me my life. Had any person been near to have taken hold of my hand, and have called to me, I should have been easily recovered, whilst, notwithstanding my struggles, and the violence with which I fell out of my cot, I lay nevertheless for some time partly upon a chest, and partly upon the cot, without being able to recover myself. I cannot help thinking that, but for the violent motion of the ship (as it was blowing a gale of wind), and the noise from every thing about me, that paroxysm of Night-Mare would have proved fatal. The disease had then gained very much upon me, and was at its greatest height.

Although instances of a fatal termination of this disease may be rare; it is not so, to find it degenerate into Epilepsy, of which it is frequently the forerunner, and to which, when it has become habitual, it appears to bear a great affinity. There is however a great difference in the degree of danger, between an accidental and an habitual Night-Mare, which we shall have occasion to notice hereafter.

I shall begin by describing this affection as it most commonly occurs, pointing out the various degrees and varieties of it, and the persons most subject to it. Its remote and proximate causes will be the next subject of consideration, and lastly the means necessary to be pursued for avoiding it, as well as those likely to afford immediate relief.

This affection has been very elegantly and correctly described both by physicians and poets. There are two descriptions of the latter kind which I cannot help placing before the reader; the first is given by the Prince of Latin Poets; the other by one, (not the least,) of our own country.

Ac veluti in somnis, oculos ubi languida pressit
Nocte quies, nequidquam avidos extendere cursus
Velle videmur, et in mediis conatibus ægri
Succidimus; non lingua valet, non corpore notæ
Sufficiunt vires, nec vox aut verba sequuntur.
Virgil. Æneid. Lib. xii. v. 909. et sequent.

In broken dreams the image rose
Of varied perils, pains, and woes;
His steed now flounders in the brake,
Now sinks his barge upon the lake;
Now leader of a broken host,
His standard falls, his honour’s lost.
Then—from my couch may heavenly might
Chase that worst phantom of the night!
Lady of the Lake, Canto 1. xxiii.

In tracing out the symptoms and mode of attack, I shall particularize those symptoms which I have experienced in my own person, and take notice likewise of those described by other writers on the subject.

First then, this disease attacks always during sleep. This is a truth of which I am now well assured, although frequently the evidence of my senses has apparently produced a contrary conviction. Whatever may be the situation of the patient at the moment previous to the invasion of the disease, he is at that moment asleep, although the transition from the waking to the sleeping state may be so rapid as to be imperceptible. I will explain this part of the subject more fully by and by, at present we will assume the fact, and proceed to enumerate the symptoms. If the patient be in a profound sleep, he is generally alarmed with some disagreeable dream; he imagines that he is exposed to some danger, or pursued by some enemy which he cannot avoid; frequently he feels as though his legs were tied, or deprived of the power of motion; sometimes he fancies himself confined in some very close place, where he is in danger of suffocation, or at the bottom of a cavern or vault from which his return is intercepted. It will not unfrequently happen, that this is the whole of the sensation which the disease, for the time, produces, when it goes off without creating any further annoyance: the patient either falls into an oblivious slumber, or the alarming dream is succeeded by one more pleasant. In this case the disease is not fully formed, but only threatens an invasion; it proves however that the pre-disposition to it exists, and that the person is in danger of it. But when the paroxysm does actually take place, the uneasiness of the patient in his dream rapidly increases, till it ends in a kind of consciousness that he is in bed, and asleep; but he feels to be oppressed with some weight which confines him upon his back and prevents his breathing, which is now become extremely laborious, so that the lungs cannot be fully inflated by any effort he can make. The sensation is now the most painful that can be conceived; the person becomes every instant more awake and conscious of his situation: he makes violent efforts to move his limbs, especially his arms, with a view of throwing off the incumbent weight, but not a muscle will obey the impulse of the will: he groans aloud, if he has strength to do it, while every effort he makes seems to exhaust the little remaining vigour. The difficulty of breathing goes on increasing, so that every breath he draws, seems to be almost the last that he is likely to draw; the heart generally moves with increased velocity, sometimes is affected with palpitation; the countenance appears ghastly, and the eyes are half open. The patient, if left to himself, lies in this state generally about a minute or two, when he recovers all at once the power of volition: upon which he either jumps up in bed, or instantly changes his position, so as to wake himself thoroughly. If this be not done, the paroxysm is very apt to recur again immediately, as the propensity to sleep is almost irresistible, and, if yielded to, another paroxysm of Night-Mare is for the most part inevitable.

Where the Disease has not established itself by very frequent recurrence, the patient generally feels little inconvenience from it when thoroughly awoke; but where it is habitual, there will generally be felt some confusion in the head, with singing in the ears, a sense of weight about the forehead, and, if in the dark, luminous spectra are frequently seen, such as appear to persons who immediately after gazing on a strong light, close their eyes. The pulse, I believe, will in all instances be found to be considerably accelerated; in my own case the motion of the heart amounts almost to a palpitation.

I do not find this symptom taken notice of by any writer on the subject, excepting Etmuller, whose accuracy in tracing the history of every disease allowed no symptom to escape him. When reasoning on the phenomena which this affection exhibits, “et cum etiam simul sub respirationis defectu imminuta plus minus evadat sanguinis circulatio, ob id ab eodem infarcti pulmones anxietatem insignem præcordiorum inducunt: sicut dum evigilant tales ægri, cor insignitur palpitat, quod testatur motum convulsivum.”—This palpitation of the heart grows stronger in proportion to the length of the paroxysm, or the difficulty the patient finds in waking himself.

There is, however, another symptom, which, as far as I am able to learn, is very frequent, though not noticed by medical writers. (Scilicet.) Priapismus interdum vix tolerabilis et aliquamdiu post paroxysmi solutionem persistens. I have noticed this symptom here, as I intend presently to draw some inference from it. A sense of weight at the stomach, and an unpleasant taste in the mouth will generally be found to remain after the paroxysm, though seldom noticed, as it is not suspected to have any connexion with the Night-Mare.

These are the most ordinary symptoms, and such as generally happen in almost all paroxysms of Night-Mare; there are, however, other symptoms which occasionally occur, and which sometimes cause no small alarm to the patient. It frequently happens too, that the paroxysm goes off without the patient waking, and in that case is productive of strange hallucination to the person who is not accustomed to these paroxysms. It is by no means an uncommon thing for the person labouring under Night-Mare to see, or at least to imagine that he sees, some figure, either human, or otherwise, standing by him, threatening him, or deriding, or oppressing him. This circumstance has been productive of considerable misapprehensions and mistakes, not only with persons of weak minds, but likewise with those whose intellectual faculties have been greatly improved.—These visions are various, as are likewise the senses which become thus hallucinated; not only the sight, but the hearing, and the touch, are frequently imposed on. These hallucinations have so often occurred to myself, that they have long been rendered quite familiar, although they are still sometimes productive of very laughable mistakes. As they are more frequently, however, of the terrific cast, they act very powerfully on the minds of those who are not acquainted with them, and produce terrors which I verily believe sometimes prove fatal. I shall give some instances of these kinds of visions which I have had from the most indubitable authority, and I do not doubt but that many readers will find in their own recollections a number of circumstances apparently incredible, which will easily admit of the same solution. I must first premise, that the degree of consciousness during a paroxysm of Night-Mare is so much greater than ever happens in a dream, that the person who has had a vision of this kind cannot easily bring himself to acknowledge the deceit, unless, as often happens, he wakes out of the paroxysm, and finds himself in a very different place to what he must have been in for such a transaction to have occurred. When however, all the circumstances of time and place concur with the vision, which sometimes happens, and the patient does not wake in the paroxysm, but continues asleep for some time after, the transactions which occurred during the paroxysm of Night-Mare, and those of the dreams which took place during profound sleep are so very different as to the impression they have left on the sensorium, that there is no possibility of confounding them with one another. Indeed I know no way which a man has of convincing himself that the vision which has occurred during a paroxysm of Night-Mare, (if it be consistent in point of time and place,) is not real, unless he could have the evidence of other persons to the contrary who were present, and awake at the time, or that these hallucinations were rendered familiar to him by frequent repetition. I shall mention some circumstances here, which have occurred to myself and to others, which will place this subject in a clearer point of view.

The first case of this kind which I shall relate, I had from the mouth of a person of undoubted veracity, who never understood the nature of the hallucination; but who, to the day of his death, was convinced that he had received a supernatural visitation.

Mr. T——, a dissenting minister, was on a journey in Suffolk, and slept at the house of a friend. He was desired by the master of the family not to disturb himself in the morning till he was called; supposing that he was fatigued and would require repose. Mr. T——, however, did not sleep very sound, he awoke often, and as it was in the summer season, and he had no watch with him, began to grow anxious about the time, as it had been long day-light: he thought, however, on what he had been told over night, and was expecting very shortly to be called to breakfast. He described himself as being awoke out of his sleep by hearing distinctly some person in an adjoining room get out of bed, and walk across the room to a door communicating with his own, which he heard opened, and a voice called to him, repeating distinctly his name, three times. He supposes that he immediately afterwards fell asleep, and did not wake till some time after, when, he observed, he had a paroxysm of Night-Mare; on recovering, however, from this, he instantly got up, supposing that he had overslept himself, and that the family would be waiting for him to breakfast. He was greatly surprised to find the doors and the windows of the house all close shut, and no one of the family stirring; it was in fact only five o’clock in the morning. He consequently returned to bed, and slept comfortably till breakfast was really announced to him. He related to the family the adventure which had occurred to him, which seemed to cause little surprize, but produced tears from some of them: they informed him that nobody slept in the adjoining room, but that it had formerly been occupied by their son, who had been several years at sea; that they had heard nothing of him for some months, and entertained no doubt of his being dead, and this circumstance served to confirm them in their opinion, and left no doubt in the minds of all present that Mr. T—— had received a supernatural visitation. Mr. T—— was himself of the same opinion to the day of his death, although the young gentleman whose fate was considered so well ascertained, proved in the sequel to be alive.

This, I am convinced, was a genuine case of Night-Mare, as I have very frequently experienced something very similar to it, as I shall explain by and by.

The next case I shall notice is that of a student in medicine, whom I have often heard seriously relating the circumstance, and who could never be persuaded that there was a possibility of his being deceived, till some years afterwards, when another hallucination, equally strong, but inconsistent as to time and place, pointed out to him the fallacy of such visions. At the age of fifteen or sixteen, he described himself as lying awake in the night, when he heard distinctly some one coming up the stairs, and immediately afterwards saw a female figure enter his bed-room, which he supposed to be his mother, who had died while he was in his infancy, but whose person had been frequently described to him. The figure before him answered precisely to the idea he had formed of her person, and excited in him considerable alarm. She beckoned to him to get up and follow her, which, after many ineffectual attempts, he at length accomplished, and followed her to the bottom of the stairs, where he lost sight of her, and returned to bed. This vision was repeated, either the next night, or shortly after, but with this difference, that he found himself unable to get out of bed, and the spectre quitted the room with threatening gestures, and an indignant aspect. This vision made a deep impression on the mind of the young gentleman, and no reasoning upon the subject could convince him of the hallucination of the vision, till a repetition of it several years afterwards, under circumstances equally strong, but impossible in themselves, produced that conviction which reasoning could not effect.

I know a gentleman, who is living at this moment, a slave to a needless terror, arising from a circumstance which admits easily of explanation from this cause. He was lying in bed with his wife, and, as he supposed, quite awake; when he felt distinctly the impression of some person’s hand upon his right shoulder, which created such a degree of alarm that he dared not to move himself in bed, and indeed could not if he had possessed the courage. It was some time before he had it in his power to awake his wife, and to communicate to her the subject of his terror. The shoulder which had felt the impression of the hand, continued to feel benumbed and uncomfortable for some time; it had been uncovered, and most probably the cold to which it was exposed, was the sole cause of the phenomenon. This gentleman, I know, was, when at school, very subject to the Night-Mare: this circumstance, however, was productive of the greatest terror, as he never assigned to it any other cause than that of supernatural agency, and considered it as a warning of some impending calamity. More than ten years have elapsed since it occurred, and though the terror it occasioned has been greatly diminished by time, it has not yet subsided entirely.

The case which I am now about to relate, is a remarkable instance of the forcible impression which these visions are capable of making on the mind, and is worthy of the utmost consideration of those persons who may feel the strongest conviction in their own breasts that they have received some supernatural visitation. Mr. B * * *, the young gentleman who is the subject of it, is at this moment a student of medicine in one of the London hospitals, and the fact I am going to relate is very well known to all his friends and acquaintances. His first attendance at the hospitals was about six years ago, and he was then of an age considerably less than gentlemen usually are, who enter on the public courses of medicine. He had never before been in town, and his mind, naturally timid and irritable, was at that moment disposed in an extraordinary manner to reflections of a terrific and alarming nature. He had no small dread on his mind, of the robbers and house-breakers of the metropolis, of whose daring exploits he had heard many terrible stories; added to this, he had conceived a fresh stock of ideas of horror from his first introduction to the dissecting rooms, so that it may readily be imagined, when alone and in the dark, he could never be perfectly at his ease. Indeed I have often known some of the bravest men, who would face death in the time of action, or of imminent danger, with undaunted courage, who nevertheless were as timid as children, where they have any idea of supernatural appearances: and I have even observed this timidity in officers of rank, who have been distinguished and rewarded by the country for their gallant exploits. Mr. B * * *, however, thus relates the incident: he was living in lodgings in the vicinity of St. Thomas’s Hospital, and happening to wake in the middle of the night, as he imagined, he heard the sound of footsteps approach his door, which was quickly opened, and he saw distinctly a man enter the room, whom he described as having on a blue coat with white buttons; the moon was shining into the room, and he could see every object distinctly: the man approached the side of the bed, when Mr. B * * * drew himself under the bed-clothes; in this situation he heard distinctly, the ticking of his watch under the pillow, where he had always taken the precaution to secure it: in a short time he felt the hand of the man rummaging the pillow, as if with the design of seizing the watch; upon which Mr. B * * * drew the watch gently into the bed, and concealed it there: he still, however, felt distinctly the man’s hand under the pillow, and was now in the greatest alarm imaginable, not only for his watch, but for his personal safety, and began to complain aloud of pain in the bowels, accusing the supper he had eaten as being the cause of the disturbance, with the idea, that by this stratagem he might succeed in getting up and going out of the room, without exciting any suspicion in the man, who was still (as he supposed) standing by the bed-side, as to the true cause of his getting up. He at length ventured to get out on the opposite side of the bed, and hastened towards the door: the man followed him, and he says he felt distinctly the impression of his hand upon one shoulder, just as he was escaping out of the door. He ran instantly into the bed-room of the man who kept the house, and gave an alarm. This person immediately arose and called in the watchman; the house was searched from top to bottom very strictly, but no person of any description could be found: the doors and windows were all secure, nor was there a possibility of any one getting in or out of the house unobserved. Mr. B * * *, however, could not be satisfied on this score; the evidence of his own senses, which had never before deceived him, appeared to him to be superior to all other evidence whatsoever. He quitted his lodgings the next day, and retained pertinaciously the opinion, that what he had seen was real, until more than a year afterwards, when being at sea, he was again visited by this extraordinary affection, and was equally certain of the reality of his vision. But in this case, he had the opportunity of proving, in the most satisfactory manner, that it was a delusion. He thought that one of his comrades had come to the side of his hammock, and lifting it up, pressed his breast against the beams, so that he could scarcely breathe. On recovering from this seemingly dangerous predicament, he jumped out of bed and made no less outcry about this affair, than he had done about the former. The proof, however, in this case, was much easier to procure. A sentry, whose post was close to his hammock, could vouch for no person having approached the spot; and the gentleman, whom he thought he had seen lifting up his hammock, was abed and asleep. Mr. B * * * has since this time been frequently affected by Night-Mare, and being now under no alarm about the visions, can always contemplate them calmly, and satisfy himself thoroughly of their delusion.

I could recapitulate a number of instances of the same kind, but shall only take notice of one or two more, which occurred to myself; such as tend to throw a light upon the subject, and which, from their consistency, left me in great doubt whether they were real or visionary occurrences.

In the month of February, 1814, I was living in the same house with a young gentleman, the son of a peer of the United Kingdom, who was at that time under my care in a very alarming state of health; and who had been, for several days, in a state of violent delirium. The close attention which his case required from me, together with a degree of personal attachment to him, had rendered me extremely anxious about him; and as my usual hours of sleep suffered a great degree of interruption from the attendance given to him, I was from that cause alone rendered more than usually liable to the attacks of Night-Mare, which consequently intruded itself every night upon my slumbers. The young gentleman in question, from the violence of his delirium, was with great difficulty kept in bed; and had once or twice eluded the vigilance of his attendants, and jumped out of bed: an accident, of which I was every moment dreading a repetition. I awoke from my sleep one morning about four o’clock, at least it appeared to me that I awoke, and heard distinctly the voice of this young gentleman, who seemed to be coming hastily up the stairs leading to my apartment, calling me by name, in the manner he was accustomed to do in his delirium; and immediately after I saw him standing by my bed-side holding the curtains open, expressing all that wildness in his looks, which accompanies violent delirium. At the same moment, I heard the voices of his two attendants coming up the stairs in search of him, who likewise came into the room, and took him away. During all this scene I was attempting to speak, but could not articulate; I thought, however, that I succeeded in attempting to get out of bed, and assisting his attendants in removing him out of the room, after which I returned to bed, and instantly fell asleep. When I waited upon my patient in the morning, I was not a little surprised to find that he was asleep; and was utterly confounded on being told that he had been so all night; and as this was the first sleep he had enjoyed for three or four days, the attendants were very minute in detailing the whole particulars of it. Although this account appeared inconsistent with what I conceived I had seen, and with what I concluded they knew as well as myself, I did not for some time perceive the error into which I had been led, till I observed, that some of my questions and remarks were not intelligible; then I began to suspect the true source of the error, which I should never have discovered, had not experience rendered these hallucinations familiar to me. But the whole of this transaction had so much consistency and probability in it, that I might, under different circumstances, have remained for ever ignorant of having been imposed upon, in this instance, by my senses. The idea which I myself entertained on the subject was this; that when the person came to my bed-side, I was actually labouring under a paroxysm of Night-Mare, which prevented my speaking to him, (a circumstance which has often happened to me in the morning, when my servant has come to announce to me that it was time to rise;) but that the arrival of the attendants, and the noise and confusion created by the transaction, had dispelled the Night-Mare, and I was then able to get up and render the necessary assistance. The whole of this was probable enough, but no part of it true; for the whole was a dream: the first part of which occurred during the state of Night-Mare, which is a species of somnium; a state neither of sleeping or waking, but essentially different from both; a state in which I possessed a degree of consciousness which never accompanies sleep; so much, indeed, that I was aware I was in bed, and was labouring under a paroxysm of Night-Mare. This paroxysm continued but a short time, and went off again before I awoke thoroughly. In short, having now no disturbance I continued to sleep for some time, till a second paroxysm of Incubus awoke me. Had I awoke in the first paroxysm, I should have instantly perceived the fallacy of the vision; but not having had that conviction, and the dream being continued after the paroxysm of Incubus had ceased, without any great deviation from probability, I had no means of conviction left but the evidence of the persons themselves, the former part of the transaction having made precisely the same impression on the mind, as if such a thing had really occurred; and although the recollection of the latter part of it was not so very distinct, but on the contrary, rather confused, yet the degree of certainty which attached itself to the principal part of the transaction, was such as would have prevented all suspicion. In fact, the extreme probability of the whole, would have left in my mind a thorough conviction that such a transaction had really occurred, and the idea would have been so associated with the rest of the train of ideas which related to the person in question, that in all probability I should never have thought of his illness without calling to mind, at the same time, his appearance at my bed-side in the middle of the night, in a state of violent delirium, and the scene of confusion to which it gave rise.

One more instance I will mention, merely to shew how complete the conviction of the mind frequently is, where the bounds of probability or even of possibility have not been exceeded by the vision or hallucination, which takes place in Night-Mare.

This affection has always attacked me at sea with greater severity than on shore. I have already hinted, that during the paroxysms, I have frequently possessed that degree of consciousness, that I have been aware that my servant was knocking at my door, announcing to me the hour of the morning. Experience has repeatedly proved to me that I was correct in my perceptions; often too have I found by experience, that I was widely mistaken. The instance I am going to relate happened on board one of his Majesty’s ships at Spithead: I was lying in my cot, labouring under a paroxysm of Night-Mare; it was broad day-light, and I could perceive distinctly all the objects in my cabin, which came within the range of vision; I was likewise conscious of labouring at the moment under this disagreeable malady, when I heard distinctly a person approach the cabin door, and immediately after knock at it, and a well known voice of a Quarter-master, who was often in the habit of calling me, after repeating my name, informed me that the Captain wished to see me immediately. I was unable to make any answer to this, although I attempted it, and both the knocking and the message were repeated, I do not now remember whether twice or thrice; I heard, however, the person retire from the cabin door. As soon as I recovered, I rose and hastened to obey the summons which I had received, but was soon informed that the Captain was not on board, and that no messenger of any kind had been near my cabin.

These instances I have adduced, to shew how very strong a sense of conviction they impress on the mind of their reality, when there is any degree of probability in the transaction, and the evidence afforded by the senses is no less striking when the vision itself is ever so extravagant. When, however, the patient awakes immediately out of the Night-Mare, he is generally at once convinced of the hallucination; unless in cases of extreme probability like the last mentioned instance. But when the paroxysm of Night-Mare goes off, and the patient continues asleep for some time after, the confusion of ideas which succeed on waking is very perplexing. If he has had any vision during the Night-Mare, the impression of it remains on the mind like any transaction which has really occurred, and he has no method of ascertaining the true nature of the case, but by considering the degree of probability, and comparing it with his past experience of similar hallucinations; if he has no such experience, it is ten to one whether he will ever arrive at a true understanding of the affair.

Hence it is easy to conceive, how many well-meaning persons may frequently deceive themselves and others with the belief of having seen spectres, heard voices, &c. in the dead of the night; and it is not very improbable that a well-grounded conviction in the mind of any person, of having received a supernatural warning of their approaching fate, should, under certain circumstances, be productive of the very event which was thus foreboded and dreaded. I could relate a number of instances where the visions accompanying paroxysms of Incubus, have been of the most terrific kind.[3] I think enough has been said on that subject to shew how easily a person may be deceived where he thinks he has the evidence of his own senses; and I have selected such histories in my own case to illustrate this truth by, as were least likely to be suspected of arising from fright or terror, or any cause that could be much aided by the imagination.

I wish it, however, to be understood, that I by no means intend to explain by this hypothesis, all the extraordinary accounts of supernatural operations which are given us on indubitable authority, and supported by unquestionable evidence. I am aware that there are a great many cases to which it will not apply, neither can any one principle possibly explain them all. I have been very much surprised to see a late medical writer on the subject of apparitions, attempt to explain all the cases he has adduced, by supposing the disease to exist, so ably described by Nicolai, and of which several cases have been given by Dr. Alderson of Hull.

He has himself recorded several instances of spectres, which appear to be closely connected with the death of persons at a distance, and with some of the most important circumstances in the lives of the persons who saw these appearances: he even admits the truth of these instances, yet ascribes the most important circumstances attending them to chance.

Of all the modes of solving difficulties, which mankind have ever had recourse to, this is certainly the least philosophical. In the present age however it appears to be considered still more unphilosophical to acknowledge that any phenomenon, however extraordinary, is above our comprehension.

I have been rather prolix on this subject, because I do not remember to have seen any correct account of it in any writer, although the circumstance of seeing spectres during the paroxysm of Incubus is noticed by the most ancient medical writers and others, both Greek and Roman; many of whom attributed the whole phenomenon of Ephialtes, or Incubus, to the agency of Dæmons. This affection has likewise been noticed by St. Augustine as well as other Fathers of the Church, who considered it to be the work of Dæmons, and speaks of it as a thing common in those days.—St. Augustin. De Civitate Dei, lib. 15. c. 23.—“Dæmones, scilicet, qui mulieribus se commiscent, et ab incubando Incubi dicuntur, sicuti, qui viris, et patiuntur muliebria, Succubi.” “Sunt nonnulli, qui hoc malum Incubi nomen accepisse putant, ex eo, quod Ephialte laborantes, opinantur, hominem qui illos opprimit, turpis libidinis usum ab iis exigere, seu una cum illis concumbere.”—Sennertus, Tom. ii. Liber i. part. 2. Cap. xxix. de Incubo.

Vide quæ supra de Priapismo memoravimus; necnon de Cordis palpitatione quæ revera Priapismi etiam somnorumque supradictorum causa mihi esse videtur; impulsum est nimirum in arterias pudicas plus sanguinis quam per venas revehi potest, unde partes genitales vellicantur et stimulantur, somniisque venereis, non tamen sine horrore quodam, ansa præbetur.

There is a symptom, said by Etmuller, and some others of the ancient medical writers, to occur frequently in this disease, but which I have never met with; that is, the appearance of red, or livid, or purple spots upon the limbs and body, but especially on the thighs.—These are said to remain till morning, and then disappear.

The following case is related by that celebrated Physician:

“Historiam Incubi magis ad epilepticos, quam paralyticos affectus 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.