If the patient is an infant, the milk should be diluted and especially should the fat be reduced (see page 76). In severe attacks with vomiting or frequent foul stools, all food should be stopped for at least twelve hours and all milk for a longer time, and the bowels freely moved by a cathartic. _Why is a cathartic necessary if the movements are already frequent?_ Such movements are nearly always due to an irritation in the bowel, set up by the fermenting food which has not been digested. The diarrhoea is Nature's effort to get rid of the irritant. Nothing to stop the movements should be given until the bowels have been thoroughly cleared by the treatment mentioned. BAD HABITS _What are the most common bad habits of young children?_ Sucking, nail-biting, dirt-eating, bed-wetting, and masturbation. _What do children suck?_ Most frequently the thumbs or fingers, sometimes the clothing or blanket; often the "pacifier" or rubber nipple. _When is this habit most frequently seen?_ It begins in quite early infancy, and if not broken may last until children are six or seven years old. _Is the sucking habit a harmful one?_ When persisted in it may produce a misshapen mouth or fingers. It constantly stimulates the flow of saliva and certainly aggravates disturbances of digestion during which the sucking habit is likely to be practised. It may lead to thrush or other forms of infection of the mouth. It is not necessary as a means of quieting a child, though it may in some degree cover up the consequences of bad feeding or bad training. On no account should the habit of sucking the "pacifier" be allowed as a means of putting children to sleep, or of quieting them while restless from dentition or indigestion. _How is the sucking habit to be controlled?_ One should be sure in the first place that the constant sucking of fingers is not due to hunger from insufficient food. Sucking of the hands may often be controlled by wearing mittens or fastening the hands to the sides during sleep. In more obstinate cases it may be necessary to confine the elbow by small pasteboard splints to prevent the child from bending the arm so as to get the hand to the mouth. _When are nail-biting and dirt-eating seen, and how are they to be controlled?_ These habits belong especially to children over three years old. They are seen particularly in those who are excessively nervous or whose general health is below par; sometimes in those who develop serious nervous diseases later in life. Children with such tendencies should be closely watched, and every means used to break up these habits early. Dirt-eating is a morbid craving which is rarely seen in a normal child. _At what age may a child generally be expected to go without wetting the bed during the night?_