Whatever may be the age and circumstances of an individual, he ought to retire for rest with a cheerful mind. All anxiety about the future, all regret about the past, all plans even, in regard to the business or amusement of the morrow, should be kept wholly out of the mind. We should yield ourselves up to the arms of sleep with the same quietude as if life were finished, and we had nothing more to do or think of. SEC. 9. _Quality of Sleep._ The soundness, as well as other qualities, of sleep, differs greatly in different individuals; and even in the same night, with the same individual in different circumstances. The first four or five hours of sleep are usually more sound than the remainder. Hardly anything will interrupt the repose of some persons during the early part of the night, while they awake afterwards at the slightest noise or movement--the chirping of a cricket, or the playing of a kitten. In profound sleep, we probably dream very little, if at all; but in other circumstances, we are constantly disturbed by dreaming, and sometimes start and wake in the greatest anxiety or horror. Nightmare is generally accompanied by dreams of the most distressing kind. We imagine a wild beast, or a serpent in pursuit of us; or a rock is detached from some neighboring cliff, and is about to roll upon and crush us; and yet all our efforts to fly are unavailing. We seem chained to the spot; but while in the very jaws of destruction, perhaps we awake, trembling, and palpitating, and weary, as if something of a serious nature had really happened. In the case of nightmare, it is more than probable that we fall asleep with our stomachs too heavily loaded with food, or with a smaller quantity of that which is highly indigestible. Or it may sometimes arise from an improper position of the body, such as disturbs the action of the stomach or lungs, or of both these organs. Lying on the back, when we first go to sleep, is very apt to produce nightmare. But distressing dreams often follow an evening of anxious cares, especially if those cares preyed upon us for the last half hour; and also after late suppers, even if they are light--and late reading. Hence the injunctions of the last section. Hence, too, the importance of taking our last meal two or three hours before sleep, and of engaging, during these hours, in cheerful conversation, and in the social and private duties of religion. Family and private worship, in the evening, are enjoined no less by philosophy than they are by christianity; and every young mother will do well to understand this matter, and train her offspring accordingly.