MOTHER: That of a man weighs about three pounds. An elephant’s weighs eight or ten pounds, and that is the heaviest of any we know. The brain must be used, the same as the muscles, if we would have it do its work well. It makes it grow and does it good when we study and think. As it was made to think about something, we should give it good things to think about. If it is lazy, it will lose the power to work, just as the muscles do, and if used, it will grow stronger and can do still harder work. HELEN: And does it ever need rest? MOTHER: Certainly; it must rest, the same as the muscles. People sometimes hurt the brain by working it very hard and letting the muscles do nothing. PERCY: But how can it rest? We can’t stop thinking. MOTHER: No; we think of something all the time we are awake, so the best way to rest the brain is to take plenty of sleep. Sometimes a part of it keeps awake while the body is asleep, and then we say we had a dream. Another way to rest the mind is to set the muscles at work after we have been reading or studying. Boys and girls in school should spend part of each day working, or in some way using their muscles in the open air. ELMER: I should think the master of the body-house would want to look outside of his little room sometimes. MOTHER: Yes, he does; and the cupola of which we have been talking has two wonderful windows. AMY: Oh, I know what they are! They are our eyes. MOTHER: Yes, and through them the master looks out and sees all that is passing around him. HELEN: I should think there ought to be windows on all sides of his room. He can look out only one way. MOTHER: But you see this cupola is placed on top of a tower we call the neck, which turns easily and quickly, and, besides, the whole house can “face about” in an instant, so he can look other ways than straight ahead, with no trouble. PERCY: Why do you call the brain the master of the house, mother? MOTHER: Because it tells the feet, hands, tongue, eyes, and all other parts of the body what to do, and they obey it. Sometimes we find a bad master in one of these beautiful houses. He tells the feet to go to a saloon. He tells the tongue to ask for beer and other kinds of strong drink. He tells the hand to lift the glass to his lips. It may be he knows he is taking poison into the house, which will make his servants, the muscles, unfit for work. Perhaps he knows, too, that the drink will hurt himself more than any other part of the body-house, for it puts him to sleep when he ought to be awake telling his servants what to do, yet he does it, and often suffers all the rest of his life for his folly. ELMER: Does alcohol hurt the brain? MOTHER: Surely it does. It makes the blood impure, so it can not furnish good food for the brain. It causes more blood to go to the head than ought to be there. It makes people mad, crazy, or insane.