THE MYSTERY OF SLEEP.
THE most wonderful events in the world are the most common. If the sun appeared, says Carlyle, only once in a long term of years, how excited everybody would be. But the miracle takes place every day unregarded. The most wonderful thing that happens to man from the cradle to the grave is also a daily event, and it excites hardly any wonder or cariosity. That phenomenon is sleep. We go to bed at night, and expect sleep as a matter of course. It approaches us with no sense of surprise or apprehension on our part ; we pass within the ivory gate with as little concern as we walk down the street, and yet sleep is as wonderful as death, to which not a few poets have likened it. Only the confirmed victim of insomnia realises its beneficent influence, to the rest it is as commonplace as breakfast. And yet sleep is not only the profoundest mystery we know, but it is the result and the accompaniment of the most remarkable changes in our bodies, themselves also subjects of deepest wonder. These changes are described in a very interesting paper iu the April number of Harper's Magazine by Dr. Andrew Wilson.
The first fact relating to sleep is that the sum total of our energy is reduced; or, as Dr. Wilson puts it, "the living engine slows down, as it were, and banks up its fires, so that its pulsations are sufficient, not for actual labour, but for merely maintaining the passive flow of force within the or- ganism." Whether this reduction of the play of bodily force Loses or merely accompanies sleep it might be bard to say. It is a beautiful thought in " The Ancient Mariner" that sleep is a blessed influence descending from above, but we suppose science will not listen to that, though it is not incompatible with the idea. of the preparation for sleep by the bodily forces. The scientific statement would be that there is a general displacement and rearrangement of molecules, but that does not help us much, for the movements of molecules are unintelligible as an ultimate expression of why things are so and so. Then the work of the glands is slackened, they are not called on to secrete so many products from the blood. The most striking fact is the change in temperature. The temperature of the human body rises at a quick rate from 6 a.m. to 10 or 11 a.m., increases at a slower rate from flat time to 6 p.m., and then falls, reaching the minimum point at about 4 a.m. It is probable, by the way, that colds are often caught in bed at this last hoar, especially by rest- less sleepers who partially divest themselves of their bed- clothes, and so are exposed at the very time when the body demands the greatest protection. At this hour, too, the tissue-changes are reduced to a minimum. The pulsations of the engine are, in a word, at their feeblest. The brain becomes paler, the appearance of even the ruddiest people grows more pallid, the resemblance to death is more apparent, so that it seems natural to speak of the dead as asleep, and to say with Shelley in " Queen Mab,"—
" How wonderful is Death, Death and his brother Sleep !"
A learned author quoted by Dr. Wilson attributes the real cause of sleep to " the changes which the nerve elements of the brain undergo as the result of fatigue." But Dr. Wilson himself holds that it is in the brain cells that we shall probably find such explanation of sleep as science can give us. It is known to-day that the brain is composed of hundreds of millions of cells, each an independent unit, though all united in a greater and more complex unity. He suggests that this unity of action is accomplished by the transmission of impulses from one cell to another, by temporary contact of the fibres, and this would be the normal condition of things in what we may call "business hours," when the telephonic exchanges between the cells are in full operation. But, `• when the business of the day is over, and the central telegraphic or telephonic exchange is no longer occupied with its busy work, we can conversely imagine the withdrawal of the processes of the cells, and of their breaking their connections for a brief season, which is devoted to their recuperation." That season of recuperation is what we know as sleep.
This is an ingenious and interesting theory, and is, we suppose, quite in accord with the latest scientific investigation. It may be said, in passing, that there seems no reason why physiology should not devote morn energy than it has done to
the investigation of the problem of sleep, since so much in regard to human health depends upon accurate knowledge of its conditions. if we could induce sleep without the use of drugs what a brighter world it would be for many who now suffer those prolonged and dreary tortures which only the sleepless know. We are, of course, aware that hypnotism and mesmerism are poweiful agencies for putting patients to sleep; but even they sometimes fail, and they are as objectionable as drugs. If the problem lies in securing the quiescence of the brain cells, or, in the metaphor of Dr. Wilson, in the shutting off of the telephonic exchange, it ought not to be impossible for science to get at that part of the human organism, witness its condition, and devise means for the breaking of the contact which maintains brain activity.
Bat all this science, interesting and useful as it is, leaves the mystery where it was. We see clearly what physiological phenomena accompany sleep, but what of sleep itself, what of the human soul lately so active, now buried in a repose as still as death ? Dues the soul itself, as it were, sleep ? Does it, like the body, need repose ? What happens to the mental and moral powers of man when overcome by slumber ? Is the mind liberated from the bonds of time and place, and can it visit then " worlds not realised " ? What of the strange phenomena of our dreams, wherein ordinary and familiar secular events connected palpably with some of our daily experiences are either blended with others not so connected or are turned upside-down, and presented in an unmeaning fantasy which, nevertheless, seems at the time natural? Is our full normal consciousness there? Hardly, or the dream could not be so incongruous and impossible. Yet a partial consciousness there must be, or we could not recall the dream in the morning. And what of those strangest, but well-attested, of all dreams, in which the dreamer sees with vivid intensity an event in the future? If the sleeping form held the complete and normal conscious- ness with the brain fuoctioning iu the usual way, one would suppose the activity of the connected brain cells to be more than usually vigorous in the light of such an astounding experience; yet the very sleep in which the dream occurs depends, we are told, on the quiescence of these cells. Can it be possible, then, that in sleep, whatever the physical accompaniments, the soul does become at least partly " liberated, finding the cells for the time useless as functioning organs ? In a trance is this liberation still more completely effected ? And in death is the liberation final and complete ? We know nothing, perhaps we never shall know, but to us the problem of sleep can never be solved on any mere material ground. All the scientific problems lead up to the mysterious problems of spirit.
Previous page
