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.