SOME OBSERVATIONS

ON THE

NECESSITY, THE UTILITY, AND THE PRECURSORY SYMPTOMS

OF

SLEEP.

BY ROGER WAKEFIELD SCOTT, M. D.

Physician to the South Dispensary, Liverpool.

"Est quasi Terra incognita, in quâ quisque pro voluntate suâ vagatur, et viam diligit jam factam aut facit. Auctores de hâc re multas laudabiles et populares fabulas effixerunt, hæc verò omnia novimus esse nihil."-Brown de Epilepsia.

IT

may, perhaps, appear superfluous to dwell upon a subject so self-evident as the necessity of sleep, yet there are too many who act but little in accordance with their conviction of it; there are restless and ambitious spirits who curtail sleep of its due proportion; there are many gifted men, whose genius ill can brook the interruption entailed upon it by this physical necessity, who are apt to complain of the length of time which they are compelled to devote to it, and almost to regret that our organization is not such as to render us independent of it. By an admirable provision of Nature, the functions of those organs which are essential to the preservation of life, are removed from the control of our will, whilst the voluntary organs and intellectual faculties are placed under our own governance,

and we have the power of modifying and prolonging their states of activity within certain limits; as, however, the principle of their energy is not derived from any inexhaustible source, but soon becomes impaired and destroyed, it is necessary that there should be some periods of quiescence for its restoration, and these periods we denominate Sleep.

Since, however, there are functions which are not subject to this law of intermission, but continue uninterrupted through life, it may be asked why the other functions are not similarly regulated? It is true that we might as easily have been created independent of sleep, as otherwise; but, as it has pleased the Author of our being to render it essential to our preservation, we must consider it as consistent with the wisest purposes; and I hope that I may not be considered guilty of the presumption of attempting to fathom the designs of Providence, if I indulge in a few remarks respecting its moral necessity.

In this sphere of existence, where we are but temporary sojourners, destined to undergo a few years of probation, it would not have been compatible with the purposes of our creation to have endowed us with the highest degree of either mental or physical perfection.

The weakness of our moral nature, therefore, may have rendered us unfit to be trusted with the uninterrupted exercise of our intellectual faculties, as we but too well know how difficult it is to govern our thoughts aright, during the short period naturally allotted to their activity.

The hopes and fears, the cares and sorrows, the labours and anxieties, which occupy and distract us

by day, the temptations which assail us from without, and the evil thoughts which rise up within us; the bodily pains and diseases which our fallen nature entails upon us, render the transient oblivion of sleep one of the chief blessings that life affords us.

Such is the frailty of our nature, that the very joys of existence, and the exercise of our best and purest affections, would become indifferent and satiating, were not their value enhanced by some periods of intermission; and the anxieties and miseries which prey upon us, would destroy the energy of our frame, and drive us to insanity, did not "Nature's soft Nurse" arrest their power, by steeping our senses in forgetfulness.

The activity of our intellectual faculties themselves, were they unceasingly directed to particular objects, might endanger a similar result. Sleep, whether it consists in perfect oblivion, or the substitution of other ideas, by interrupting the chain of thoughts which have occupied us in the day, prevents them from becoming permanently and morbidly associated, and tends to preserve the due equilibrium of our mental faculties, so that it ought not to be considered so much an imperfection in our physical organization, as an admirable provision to counteract the weakness of our moral nature.

Independently of this necessity of sleep, as the means of restoration to our mental and corporeal faculties, we may trace it to a more universal and sublime origin, as one link in the great chain by which the operations of nature are connected, and which preserves the unity and harmony of the whole.

The successive periods of activity and repose, are not only accordant with the alternations of day and night,* to which they are obviously and necessarily allied, but place us in relation to the revolution of our Globe, which again connects us with the laws of the solar system, and, ultimately, with those of the universe itself. And who can contemplate, without boundless admiration, the infinite wisdom of that Power, which has "associated, through an endless gradation of operations, the sleep of a chicken on its perch, with the laws of the whole creation.”+

The more particular uses of sleep, require a more extended consideration than can be given in this brief essay; it may, however, be here observed, generally, that sleep, though it partakes so much of the semblance of death, is the very fountain of health and strength. The energy of those organs which has become exhausted by the labours of the day, whether they have consisted of mental or corporeal exertion, is restored during the quiescence of sleep; the association of morbid, or too exclusive thought, is temporarily interrupted, and thus rendered less intense and dangerous; the internal functions are carried on with more calmness and vigour; the irritation of the system subdued; the equilibrium of the circulation restored; the vital energy of the whole frame recruited, and we awake with renovated elasticity of mind and body, and fit for every laborious exertion which the duties of the day may entail

upon us.

* Libra dié somnique pares ubi fecerit horas.-Virg. Georg. lib. i. + Paley's Theology, p. 287.

I speak, here, only of that natural and healthy sleep which is the reward of labour, the crown of temperance, and the concomitant of a mind at ease, so different from those uneasy slumbers which harass the ambitious and the care-worn, and change the roses into thorns in the perfumed chambers of the great.

THE PRECURSORY SYMPTOMS OF SLEEP.

Ergo sensus abit mutatis motibus altis,

Et quoniam non est quasi quod sufficiat artus,
Debile fit corpus, languescunt omnia membra,

Brachia, palpebræque cadunt, poplitesque procumbunt.

LUCRETIUS.

The approach of our customary sleep is usually preceded by a sense of lassitude and fatigue, especially in the smaller muscles, and those which have been most exercised during the day, which is partly owing to the exhaustion of their irritability, but chiefly to the defect of nervous energy transmitted from the brain, which, also, participates in the general torpor; by the relaxation of the muscles which suspend them, the eye-lids are closed, the lower jaw falls, and the equilibrium is no longer preserved; but the body is bent forward by the law of gravity, and the head depressed towards the breast.

The limbs are frequently, and sometimes forcibly, extended, to remove some uneasy sensation in the muscles, and to assist those of inspiration in expanding the thorax; this is generally accompanied by yawning, which is owing to a deeper inspiration than ordinary, by which the heart and lungs are relieved from the congestion of blood which oppressed them.