At five months a child should not be fed or nursed between 10 P.M. and 6 A.M. At two years a child can easily go from 6 P.M. to 6 A.M. without feeding. _How should a baby be put to sleep?_ The room should be darkened and quiet, the child's hunger satisfied, and the child made generally comfortable and laid in its crib while awake. _Is rocking necessary?_ By no means. It is a habit easily acquired, but hard to break, and a very useless and sometimes injurious one. The same may be said of sucking a rubber nipple, or "pacifier," and all other devices for putting children to sleep. _What are the principal causes of disturbed sleep?_ As quiet peaceful sleep is a sign of perfect health, disorders of sleep may be produced by almost anything which is wrong with the child. 1. Habitual disturbance of sleep in infants is most frequently associated with the food or feeding. It may be from the discomfort of chronic indigestion due to improper food. In bottle-fed infants it is often the result of overfeeding; in those who are nursed it is often due to hunger. A common cause is frequent night feeding; an infant who is fed three or four times during the night is almost invariably a bad sleeper. 2. Disturbed sleep or sleeplessness may be due to causes purely nervous. Such are bad habits acquired by faulty training; as when the nursery is lighted and the child taken from its crib whenever it wakes or cries; or when some of the contrivances for inducing sleep have been used. Any excitement or romping play just before bedtime, and fears aroused by pictures or stories, are frequent causes. Children who inherit from their parents a nervous constitution are especially likely to suffer thus. 3. There may be physical discomfort from cold feet, insufficient or too much clothing, or want of fresh air in the sleeping room. 4. Interference with breathing due to obstruction from large tonsils or adenoids. These cause great restlessness and lead a child to assume many different postures during sleep, often lying upon the face or upon the hands and knees. 5. Chronic pains or frequently recurring night pains may be causes of disordered sleep, when a child wakes with a sudden sharp cry. In infants this is most often due to scurvy, sometimes to syphilis. In older children it may be the earliest symptom of disease of the hip or spine. 6. Sleeplessness and disturbed sleep are frequent whenever the general condition falls much below a healthy standard; e.g., in infants who are not thriving and in children suffering from marked anaemia. _How are children who sleep too little, or whose sleep is constantly disturbed, to be treated?_ Never by the use of soothing sirups or other medicines. Successful treatment consists in the discovery and removal of the cause. _Do children ever sleep too much?_