“A Woman, fifty years old, of a good, full, fleshy, strong habit of
Body, after her Menses stop’d, was constantly tormented with this
Disorder[20].”
I might add many more instances of this kind, to shew, that the fair
sex is subject to the severe insults of this oppressive Disease; but
hope these are sufficient to excite the attention of others to make
observations of this sort, which are the more necessary, as they have
been too much neglected by writers on this subject.
When Women pass the fruitful seasons of life, and the delicate uterine
Tubes, contracting themselves, become too rigid, and resist the impetus
of the Fluids so as to prevent the usual discharges; then the Fluids,
which were formerly periodically evacuated, are amass’d, and collected
in the Body, and occasion a Plethora. Hence, Women, about that time,
often grow fat, heavy, and sickly, and become more subject to the
Night-mare; because the Heart, swell’d with redundant Blood, will bear
more heavily on the Pulmonary Veins and left Auricle, when they happen
to sleep in a supine position.
Experience declares, that there is not a more frequent primary Cause
of the Night-mare than heavy suppers of tough animal food, and large
quantities of soft, thick malt liquors, which distend, and lie long
in the Stomach; whose pressure may contribute, in many respects, to
produce this Disorder.
1st. Its pressure on the Aorta Descendens will determine a greater
quantity of Blood than usual into the Arteries that belong to the
Head; and as these turgid vessels run contiguous to the trunks of the
Intercostal and eight pair of Nerves, they may perhaps compress them so
as to render the Heart, &c. paralytic.
2d. By occupying a large space in the Abdomen, it hinders the full
contraction of the Diaphragm, and thus diminishes the cavity of the
Thorax, prevents the necessary expansion of the Lungs, and consequently
obstructs the motion of the Blood through them.
3d. Anatomy informs us, that the Diaphragm is not perpendicular to the
Spine of the Back, but forms an acute angle with it, and is extended
obliquely upwards to the Sternum[21]. Hence, in a supine position of
the Body, the Diaphragm may be considered as an inclin’d plane, upon
which the surcharg’d Stomach must rest; and its weight on this part
will increase the pressure of the Heart on the Pulmonary Veins, as it
is connected to the opposite side of the Diaphragm by the Pericardium.
Every one knows that a hearty meal disposes People to sleep. This
effect was commonly attributed to the pressure of the Stomach on the
descending Aorta: but Doctor Stuart has oppos’d that theory[22]. Doctor
Haller has seconded him, and has given his reasons for it. He says,
“Si exquisitiori Anatome in situm Ventriculi & Aortæ inquisiveris,
reperies vix unquam Aortam a Ventriculo comprimi posse. Dum enim
distenditur, antrorsum recedit, et Curvaturam parvam retrorsum ostendit
Aortæ, quæ ea Curvatura, interjecto Pancreate, comprehenditur[23]”
This is certainly a just account of the appearance of the Stomach, when
it is distended in a dead Body, where the Integuments of the Abdomen,
and all resistance to the Stomach’s rising, is taken away: but, if we
consider the Stomach distended by any means in a living Body, where
these Integuments still remain in an active state, and resist the
motion of the Stomach forwards and upwards; then a great part of its
pressure must fall on the Aorta, and confirm the old opinion. That
part of the Diaphragm, through which the Oesophagus passes, must be
the center of motion in this case; and allowing, that the Stomach
moves a little upwards and forwards, in a distended state, yet, as the
Abdominal Viscera are in such a fluid or fluctuating condition, that
place, which may be deserted by the distention of the Stomach, will be
fill’d up by the Pancreas; and by this means, the Aorta may suffer as
great a pressure as if it was immediately in contact with the Stomach:
the argument, which that industrious Gentleman adds, may be owing to
the peculiarity of his own constitution; viz. “Imo vero aucti a pastu
veneris stimuli demonstrant, eo tempore motum Sanguinis in Aortam
descendentem potius majorem esse, quam minorem[24]”.
Doctor Haller seems to have levell’d the force of this argument against
a full Stomach being any cause of the Nightmare; but I might mention
many facts here to prove the contrary, and among the rest, might add
my own case; but, to avoid prolixity, I shall confine myself to one
instance.
A corpulent Clergyman, about fifty years old, who is very fond of
strong beer and flesh suppers, but so subject to the Night-mare, that
he is obliged to stint himself to a certain quantity every night;
whenever he happens to take an over-dose, he groans so loudly that he
often awakes all the People in the house. He has assur’d me, that, in
these fits, he imagin’d the Devil came to his bedside, seiz’d him by
the Throat, and endeavour’d to choak him. Next day he observ’d the
black impressions of his hard Fingers on his Neck. After being at a
wedding or christening, he never escapes it; and his Servant is oblig’d
to watch him all the next night, and rescue him from the Paws of Satan,
whose dreadful approach always makes him roar loud enough to awake the
Servant, if he should happen to be asleep. The Servant told me, he
always found his Master lying on his Back in the fit.
Hoffman says, “[25]Plethoricos omni cura fugere opportet decubitum
supinum, facile enim Incubo premuntur, cujus causa a Sanguinis
stagnatione in Pulmones deducenda est.”
Doctor Haller assigns a different reason for heavy suppers preventing
rest, viz. “[26]Sed etiam cibi immeabiles particulæ in Cerebro minus
facile trajactæ, comprimendo Medullam somnum minus benignum faciunt.”
It is remarkable, that this Disorder attacks People only in sleep;
which, Doctor Young says[27], is owing to the effect that sleep has
in increasing all the symptoms of a Plethora. It is true, that sleep
retards the motion of the Blood, and checks the serous secretions.
“[28].In vasis vero serosis, Lymphaticis et Nervosis circulatio parva,
et sæpe nulla est.”
There is no occasion to go about proving that the secretion of urine is
lessened in bed, for common experience sufficiently evinces it. And it
appears, by the experiments of Doctor Robinson[29] and Gorter[30], that
perspiration is considerably less in the night than in the day. It must
be allow’d, that the heat of the bed-cloaths will rarify the Blood,
and also contribute to an universal distension of the Vessels: but
all these seem to be rather the effects of lying quiet in a warm bed,
than of sleep alone. If so, People might be as readily seiz’d with the
Night-mare while they are awake in these circumstances, as when they
are asleep, which never happens.
I really can find no way of accounting for this Phænomenon, unless we
have recourse to the Soul, or that active principle within us, whose
operations, during sleep, are either greatly impeded, or altogether
suspended. It is therefore less sensible of any uneasiness in the Body
than when we are awake, and the faculties of the Mind are in action,
which is compell’d, by some innate necessity, to avoid any pain, as
soon as it perceives it in the Body.
While we are awake, lie on our Backs, and feel any uneasiness in that
position, we immediately alter it: but, in sleep, we are not so soon
conscious of the Blood’s stoppage in the Lungs, nor have we the means
of removing that dangerous obstruction so much in our power, because
the voluntary motions are then suspended, without which, the position
of the Body cannot be changed, nor the cause of the obstruction remov’d.
The insensibility of the Lungs too may contribute to render the
obstruction greater, before the Mind becomes conscious of it; for
we don’t find, that obstructions and inflammations of the Lungs are
attended with such an acute pain, as when these Disorders attack other
parts of the Body, the Liver, Spleen, and Omentum excepted.
The Night-mare may sometimes seize very plethoric Persons, when they
don’t lie directly on the Back; for part of the Heart’s weight may fall
on the Pulmonary Veins, in a lateral position of the Body.
By way of a brief recapitulation of what has been offer’d concerning
the Causes in general of this Disorder, I shall conclude this Chapter
with the following corollaries.
COR. 1. That they who have a very sensible system of Fibres,
and are soon affected by a stimulus, are least subject to the
Night-mare.
COR. 2. That sluggish, inactive constitutions are most liable
to it.
COR. 3. That the severity of the fit will be always
proportional to the sensibility of the Fibres, and the quantity of
Blood.
COR. 4. That the duration of a fit will be proportional to the
sensibility and vigour of the constitution.
COR. 5. That they who sup sparingly, and never sleep on their
Backs, are seldom or never afflicted with it.
COR. 6. That it is most common in those seasons of the year,
which most increase the volume of the Fluids: hence spring and autumn
are its most fertile periods.