Resting the Brain.—When there is no food in the stomach, it has time to rest. When we sit down or lie down, the muscles get rest. The brain is always busy except when we are asleep. No one can live even a week without sleep. If a dog is kept awake five days, it will die.
Fig. 89 —Sleeping in the position shown in the lower figure prevents free breathing and tends to cause round shoulders. The upper figure shows correct position.
Children need much more sleep than older persons. Men and women who work should have about eight hours of sleep daily to remain in good health. Children of twelve years should sleep nine hours each day; those of ten years, ten hours; those of seven years, eleven hours; and those of four years, twelve hours.
Getting the most out of Sleep.—You should go to bed every night at about the same hour. This will help you to fall asleep as soon as you are in bed. Do not sleep in the clothes which you have worn during the day, but hang them up to air, and put on a night robe.
Children should use a very low pillow, so that the body can lie straight in the bed. This gives the lungs and heart freedom to act. Do not lie on the back as this causes some of the organs to press on certain nerves and makes you dream. The windows should be opened wide because fresh air is the best aid to rest and health and keeps away tuberculosis.
PRACTICAL QUESTIONS
1. What makes the parts of the body work together?
2. Describe the surface of the brain.
3. Name the three parts of the brain.
4. Of what is the outer layer of the brain made?
5. Where is the spinal cord?
6. What are nerve fibers?
7. What work does the brain do?
8. What makes the mind good or bad?
9. What is habit?
10. How long should children sleep?
11. How can you get the most good out of sleep?