Part 1

AN

ESSAY

ON THE

Incubus, or Night-mare.

By JOHN BOND, M. D.

Ac velut in somnis oculos ubi languida pressit Nocte quies, necquicquam avidos extendere cursus Velle videmur, et in mediis conatibus ægri Succidimus; non Lingua valet non corpore notæ Sufficiunt vires, nec vox nec verba sequuntur.

VIRGIL. Æneid. xii.

LONDON: Printed for D. WILSON and T. DURHAM, at Plato’s Head, in the Strand.

MDCCLIII.

To his Excellency

ARTHUR DOBBS, Esquire,

Governor and Captain General of the Province of NORTH CAROLINA.

SIR,

Your extensive knowlege in every branch of useful and polite literature will sufficiently justify the propriety of this address, though it offers to your acceptance and protection an Essay merely medical. Besides, the subject I have chosen is in a great measure new, and must, I think, if successfully treated, prove highly useful. It seems therefore peculiarly intitled to your patronage, who are so judicious, so generous, and so zealous a promoter of every discovery which may tend to the public good. I shall not trespass farther on your patience, with the usual apologies of young Authors; nor on your modesty, with the trite panegyrics of Dedicators: the whole tenour of your life has render’d such encomiums superfluous; for you have always pursued the shortest and the surest road to fame, the real _esse quod videri velis_.

Though by this Essay I should acquire no honour from the judicious Sons of Æsculapius; this one however I am sure of, the subscribing myself

Your most obliged,

And most devoted servant,

JOHN BOND.

THE

PREFACE.

Being much afflicted with the Night-mare, self-preservation made me particularly inquisitive about it. In consulting the ancient Physicians, I found little information concerning it, except dreadful prognostics; nor could a rational account of it be expected from them, as they were unacquainted with the circulation of the Blood.

The few Authors who have mention’d it since that glorious discovery, have also given imperfect accounts of it; which are probably owing to their not having felt it themselves: for, as it only seizes People in sleep, continues but a short time, and vanishes as soon as they awake, the Physician has not an opportunity of making observations of his own, but must take all from the description of others, who have labour’d under it. These, I believe, are the reasons that the principal Writers in Physic have taken so little notice of it. These omissions however render an enquiry into the nature of this Disease the more interesting and necessary, and, at the same time, the more difficult.

Under these disadvantages I have ventur’d to communicate the result of my own observations and reflexions on it; hoping, that a greater allowance will be made for the errors in this Essay, as it is perhaps the first that ever appear’d expressly on this subject.

The Night-mare is commonly, and, I believe, justly, attributed to a stagnation of the Blood; but how this stagnation is produc’d, has not been explain’d, so far as I know, in a satisfactory manner.

I have carefully collected the observations of the ancient Physicians concerning the prognostics of this Disorder; not for ostentation, but to shew at the same time the dangerous consequences and antiquity of it, in order to make those afflicted with it the more solicitous to remove its cause in the beginning; for it may be said of the Night-mare, as of many other Disorders, _Vires acquirit eundo_.

Though the most temperate are sometimes afflicted with this Disease, yet experience shews that it is generally the offspring of excess: hence it must have been nearly _coeval_ with Bacchus (though it be omitted by the _Coan Oracle_;) and Homer probably alludes to its symptoms in the following lines:

Ως δ’ εν ὀνείρω ὀυ δύναται Φευγοντα διωκειν Οὔτ’ αρ ὁ δύναται ὑποfευγειν, ὄυθ’ ὁ διωκειν. Iliad xxii.

I have not introduc’d any thing in this Essay that did not appear serious or probable. I have therefore omitted an inquiry into the origin of many odd epithets and quaint names commonly given to this Disorder; such as _Hag-riding_, _Wizard-pressing_, _Mare-riding_, _Witch-dancing_, _&c._, nor did I think it requisite to mention particularly the _curious Charms_ adapted to each superstitious name.

My aim has been to convey my sentiments with as much brevity and perspicuity as possible. If I have transgress’d this rule, in occasionally introducing some things known, in order to explain others, it was to be the more intelligible; I therefore hope, the more learned will excuse me.

With pleasure I take this opportunity of acknowledging how much the hints I receiv’d from the instructive lectures of my ingenious Preceptor Mr. Monro, contributed to this undertaking.

AN

ESSAY

ON THE

Incubus, or Night-mare.

CHAP. I.

_Of the history and the various opinions concerning the cause of this Disorder._

In order to convey a distinct idea of the subject of the following pages, I shall, according to the old custom of medical authors, begin with the etymology of it.

Altho’ we have reason to believe, as will afterwards appear, that this Disease was known long before the Greek language, yet, the earliest account we have of it, is from the Greek authors, who call’d it Εφιαλτης, and the Romans nam’d it Incubus, both which words partly express its effects.

In our language it is generally known by the name of the NIGHT-MARE; which strange term probably arose from superstitious notions which the British had, and perhaps still have, of it. How it first obtain’d this odd appellation, I never could learn, nor is it material to know, since that name is sufficient to distinguish it from every other Disease.

The Night-mare generally seizes people sleeping on their backs, and often begins with frightful dreams, which are soon succeeded by a difficult respiration, a violent oppression on the breast, and a total privation of voluntary motion. In this agony they sigh, groan, utter indistinct sounds, and remain in the jaws of death, till, by the utmost efforts of nature, or some external assistance, they escape out of that dreadful torpid state.

As soon as they shake off that vast oppression, and are able to move the body, they are affected with a strong Palpitation, great Anxiety, Languor, and Uneasiness; which symptoms gradually abate, and are succeeded by the pleasing reflection of having escap’d such imminent danger. All these symptoms I have often felt, and hope, that whoever has had, or may have, this Disease, will readily know it by this description, which I have not only taken from my own feelings, but from the observations of many of my acquaintances, who were also afflicted with it, and from the records of the antient observators.

Before I enter into an enquiry concerning the cause of this Disorder, or attempt to assign any one for it myself, I shall first take notice of the principal opinions that have been advanc’d to account for it, and examine how far they are confident with the laws of the animal œconomy; that the judicious reader may see how necessary further enquiries into the nature of this Disorder may be.

Doctor Willis says, That the Night-mare is owing to some incongruous matter which is mix’d with the Nervous Fluid in the Cerebellum[1]. But, as he has not told us what this matter is, or how it is produced, we can afford it little credit in this enquiry; because plethoric persons, who abound with the purest and richest Blood, in whom such incongruous matter is suppos’d least to prevail, are most subject to this Disorder[2].

Bellini, who, in many other cases, is allow’d to be a pretty accurate theorist, was strangely mistaken in this, when he said, That the Night-mare is an imaginary Disease, and proceeds from the idea of some demon, which existed in the mind the day before[3].

This account is very unworthy a physician, and is a strong evidence that he never felt the heavy effects of this Disorder; otherwise he would have allow’d it to be a real Disease of the Body.

A metaphysician has laid great stress on this Disease, as an argument in defence of some of his wild opinions. He asserts, That it is owing to the operation of certains demons, which impose on, and torment, the mind in sleep[4].

This ingenious hint he took from Bellini, who probably stole it from Paracelsus’s doctrine of Archeus faber[5].

The ingenious Doctor Lower is the first author I met with, who observ’d the horizontal position of the Body, and assign’d it as a remote cause of this Disorder, but seems to attribute it immediately to a collection of Lymph in the fourth Ventricle of the Brain.

He says, “Si supine dormiant, Ventriculus ille quartus, Lympha nimium distensus, Medullam Oblongatam sua gravitate premit, ideoque fluxum liquidi Nervosi in Nervis cordi & respirationi inservientibus impedit[6].”

Perhaps he did not apply his first observation so well as might be expected from one of his abilities; for it seems needless to wait for a slow secretion of Lymph to produce this Disease, since, according to his own account, the return of the Blood from the Head, by the Jugular Veins, is in some measure prevented, and by that means a greater quantity of Blood than usual will be collected in all the vessels of the Brain; which might better answer his purpose, and more effectually obstruct the nervous influence. But before either of these causes could be removed by common methods, life would be at an end, and every fit of the Night-mare would be mortal; but that it often happens otherwise, many can testify. Doctor Lower seems to have founded this theory on the dissection of a Man who died of a Hydrocephalus, and not immediately of the Night-mare: hence that case is ill applied by Bonetus[7].

CHAP. II.

_An enquiry concerning the real cause of the Night-mare._

Having mentioned the most remarkable opinions, that have occurr’d to me concerning the cause of this Disease, and shewn them all defective, I shall next consider several circumstances attending an horizontal position of the Body in sleep, in which alone this disease is felt; and endeavour from thence to investigate the real cause of it.

Sleep is the balmy anodyne of nature; and was intended, by the all-wise Author of our being, to ease the toils of the body, dispel the cares of the mind, and to repair the losses sustain’d by the fatigue of the day. In it we see every external stimulus remov’d, the Senses lock’d up, and every Muscle relax’d, except the Heart, the Sphincters, and those concern’d in respiration. Nutrition is then principally perform’d, and then only the Fluids glide equably through the Vessels.

As many of the voluntary Muscles are imployed in keeping the Body erect, ’tis necessary that the Body should be in an inclin’d or horizontal position, in order to relax them, and promote the salutary end of sleep. Accordingly we find, that most of the brute, as well as the human Species, chuse some easy posture of this kind to sleep in.

When the human Body lies horizontally, the Blood must flow in greater abundance to the Head; and with a greater momentum, cæteris paribus, through the Carotid and Vertebral Arteries, than when the Body stands erect; because the Blood, moving through these tubes in an horizontal direction, will not so much resist the force of the Heart, as when it ascends perpendicularly contrary to its own gravity.

No one, I presume, will doubt the truth of this proposition, who reflects, that it is much easier to move any spherical body on an horizontal plane, than to raise the same body up against a perpendicular wall.

Neither will it be denied, that the quantity as well as the velocity of Blood, flowing into the Carotid and Vertebral Arteries, is increas’d by the horizontal position of the Body, if it be consider’d, that these tubes (particularly the left Carotid) arise from, and proceed almost parallel with the axis of the Aorta, where the velocity of the Blood rushing out of the Heart is greatest. Whence it follows, from Sir Isaac Newton’s second general law of motion, and from a well known axiom in hydraulics, that these Arteries must receive more Blood in the same time, than any other branches of the Aorta of the same diameter.

As the Blood must lose most of the motion which it receives from the Heart, in passing through the infinite vascular ramifications, and fine filtres of the Brain, there scarce appears, even in an erect position of the Body, any propelling power to push it back again to the Heart, except we admit the pulsation of the small Arteries belonging to the coats of the Sinuses, and its own gravity. But in an horizontal position, the Blood has not the advantage of its gravity to accelerate its motion through the Jugular Veins; therefore it must move slower, and must be more subject to obstruction in the vessels of the Brain. Hence we see the use of pillows is to promote and facilitate the return of the Blood through the Jugular Veins: hence we may also observe, the uneasiness and danger attending the too common method of making the feet of beds higher than the heads, since a stoppage of the Blood is always productive of dangerous consequences; of which any one may be soon convinc’d by stooping the Head for a short time; and it will appear, that the Blood is by this means collected in the Veins of the Face, which will produce a Vertigo, and, if long continued, may bring on an Apoplexy. Hence we sometimes hear of people dropping down dead, upon stooping to buckle their shoes. These instances should deter some from putting their pillows under their feet, in order to make the Blood settle in their faces, and to decorate the external part of their Heads at the expence of the internal.

Notwithstanding the inconveniences and bad effects which may arise from the Blood’s delay in the Brain, yet, its being sent to the Head in sleep in a greater quantity, may serve many necessary purposes, and render sleep more beneficial and refreshing to animals. First, by distending the Blood-vessels of the Cerebrum, increasing the pressure on that part, and by that means producing sleep. Secondly, by promoting the secretion, and preparing a store of animal spirits to supply the expence of the ensuing day. Thirdly, by gently encreasing the pressure of the Blood-vessels on the Cerebellum, and perhaps determining a greater quantity of the nervous influence to the Heart, respiratory Muscles, and other parts, whose Nerves spring from that fountain of life. This pressure on the Cerebellum may concur with the rarefaction of the fluids, to render the motions of these organs more regular and vigorous in sleep.

To this mechanical pressure on the Cerebellum, the illustrious Van Sweiten seems to attribute the motion of the Heart: “Cerebelli enim actio in Cor per Nervos, pendet ab ipsa actione Cordis per Arterias[8].”

Tho’ the contraction of the Heart is evidently the efficient cause of the Blood’s motion, and consequently of the secretion of these spirits in the Cerebellum, yet, without these spirits, the action of the Heart could not be performed. These two causes appear to act in a circle, and mutually depend on each other. Hence Hippocrates divin’d, ὁλον το ζωμα κυκλος εστι. These also convey the idea of a perpetuum mobile; since, as long as life lasts, an animal is really such, and far excels any machine that human art has been yet able to make, or (in the opinion of many philosophers) will ever invent.

The laborious Hoffman ascribes a great deal to this pressure on the Brain, where he says, “[9]Declivior cubitus sanguinis regressum quodammodo impedit, quia per venas jugulares descendere debet, quod elatiori capite commodius peragitur. Hinc, capite nimis demisso ac depresso, profundiores somnii cum insomniis, fiunt, universo corpore torpor inducitur. Eadem ratione, si quis facie prona velut in mensa, in somnum delabitur. Ob difficiliorem sanguinis regressum, gravitatem capiti, et ingenio stupiditatem accersit.”

“[10]Sed etiam mechanicæ causæ somnum producunt, compressio nempe Duræ Matris, aut Cerebri, quæcunque nata a Sanguine effuso, inpacto Osse, aquæ in Ventriculis copia.”

These, I hope, are sufficient to shew how far the motion of the fluids may be affected by the horizontal position of the Body; which, if duly consider’d, might be of great service in the practice of Physic; and perhaps many effectual derivations might be made, without drawing a drop of Blood. I saw a remarkable instance of this kind in a gentleman of a full habit, who, being ill of a Fever, talk’d rationally and rav’d alternately, as his head was elevated or depress’d. In acute Diseases, when the motion of the Blood is very rapid through the whole Body, the Brain must suffer greatly, on account of the horizontal position, to which people in such cases are confin’d; because, the Blood rushing violently into the Arteries of the Brain, and its return being retarded by the Jugular Veins, will remarkably contribute to produce delirious symptoms, so frequent in acute Disorders, which might be in some measure prevented, by raising the Head; for, by that means, the motion of the Blood through the Jugular Veins will be increas’d, the pressure on the Brain will be eas’d, and a safe and sudden derivation from the Head may be made, which may produce very happy effects, where no evacuation could be safely attempted.

Let us next take a view of the Heart, and consider how it may be affected by the various positions of the Body, particularly the supine one, in which the Night-mare generally invades.

The Heart is placed above the Diaphragm: the greater part of it lies in the left cavity of the Breast: its apex or point is turn’d towards the extremity of the sixth true Rib, where its pulsations are commonly felt: it adheres to the Lungs by its large vessels, and is connected to the Diaphragm by the Pericardium[11].

Thus the Heart is suspended in the Breast; and therefore must be subject to the laws of pendulous bodies, which alter their situation according to the different directions of their centers of gravity.

From the above just description of the human Heart, ’tis evident, that when the Body is erect, the parts of the Heart which are commonly called the right and left, ought to be more properly call’d the anterior and posterior.

Hence, when the Body is plac’d on the Back, these become the superior and inferior parts of the Heart.

That the Heart alters its situation in the Breast according to the different positions of the Body, and the different directions of its center of gravity, may be prov’d by the following easy experiments.

If the Finger be applied to that part of the Ribs where the pulsation is felt in an erect position; and if, at the same time, the Diaphragm be contracted strongly, the beatings become immediately weaker, because the Heart is pulled downwards by the Diaphragm.

If one lies on the left side, the point of the Heart is felt beating nearer the Spine of the Back; if we turn on our Backs, it is scarce perceptible; and if we lie on the right side, it intirely vanishes.

These alterations of the Heart’s situation in the Breast, are more remarkable in some persons than in others; and in general I have found, by repeated tryals, that they were most considerable in those who were most subject to the Night-mare.

When the Body lies supine, the Heart necessarily falls on the Vertebræ of the Spine; and therefore, by its own gravity, must compress the left Auricle and Pulmonary Veins, which, at that time, lie directly under its basis; and, by that means, the course of the Blood through the Lungs will be stop’d. Thus the Blood will be collected in the Pulmonary Vessels, and the right, or rather superior Ventricle, not being able to discharge itself into the Pulmonary Artery, will be oppressed by the Blood returning from the Extremities; which, being gather’d in the vessels about the superior part of the Heart, will increase its gravity, and consequently augment the cause of the obstruction. In this manner the return of the Blood from the Head will be prevented, the tender dilatable vessels of the Brain will be over-distended, the nervous influence obstructed, and the vital motions, in a great measure, if not altogether, stopt. This I take to be a real fit of the Night-mare, and in this manner it appears to be produc’d.

CHAP. III.

_An account of the Symptoms._

Having now discover’d what appears, to me, to be the immediate cause of the Night-mare, viz. the pressure of the Heart on the left or inferior Auricle and Pulmonary Veins, which stops the motion of the Blood through the Lungs, and occasions a general stagnation; let us examine how that hypothesis will account for the several Phænomena or Symptoms, mention’d formerly in the description of this Disease.

The first Symptoms that occur in that catalogue, are frightful Dreams, which generally are the forerunners of this Disorder. “In hoc genere (Somniorum) est Εφιαλτης quem publica persuasio quiescentes opinatur invadere, ac sentientes pondere suo gravare[12].”

I shall not here undertake to solve that Phænomenon, which has so long puzzled the Metaphysicians, nor pretend to account for all kinds of dreams in a mechanical manner.

However, every one knows that the harmony and connection between the Body and the Mind are so establish’d and constituted, while they are united, that the Diseases of the one always affect the other in a very sensible manner; and experience daily demonstrates, that violent passions of the mind produce Fevers, Fainting Fits, and other severe effects on the Body; e. contra, violent shocks of the Body, acute Diseases, &c. frequently disturb, and raise strange commotions in the Mind, or at least excite extravagant, wild ideas in it. Accordingly we find, that the most eminent Physicians have not scrupl’d to assert, that these effects are often owing to Obstructions and Inflammations of the Membranes of the Brain. If so, may not the violent distentions of the Vessels of the Brain (which always precedes and attends a fit of the Night-mare) make such strong impressions on the origin of the Nerves, or Sensorium Commune, as to occasion hideous associations of ideas, and form frightful spectres in the imagination? Are not these monstrous dreams intended as a stimulus to rouse the sentient principle in us, that we might alter the position of the Body, and by that means avoid the approaching danger? Is not the horizontal posture of the Body, which produces a Plethora in the Vessels of the Brain, and many odd sensations, the most general cause of dreams? Do they ever dream, who sleep in an erect position? Are not the luxurious and the plethoric most subject to disagreeable dreams? Is not the motion and titillation of the Animalculæ in Semine Masculino, the cause of the agreeable dreams which attend nocturnal emissions? Have females such emissions in sleep? Does not perfect sleep consist in a total suspension of the operations of the Mind? May not dreaming, in general, be consider’d as a Disorder of the Body, and justly attributed to some cause, which stimulates the Sensorium Commune, and prevents perfect rest? Do people that sleep after much fatigue, ever dream?