strong and well.

5. The brain needs pure blood, and so we must be careful to breathe pure
air.

6. The brain gets strength by exercise, just as the muscles do. Hence,
study is healthful, and makes the brain strong.

7. A good memory is very necessary, but we should not try to remember
everything.

8. It is very important that we learn how to observe things closely.

9. Exercise in the open air rests and clears the brain by helping the
blood to circulate.

10. Plenty of wholesome and simple food is necessary to keep the brain
and nerves in good health. Spices, condiments, and rich foods in general
are stimulating and harmful.

11. Plenty of sleep is needed to rest the brain and nerves.

12. It is dangerous as well as wicked to become very angry.

13. We should be careful to avoid forming bad habits of any sort, as
they are hard to break, and often adhere to one through life.