them which you do not understand; for, if you let your tongue say what your
mind knows nothing about, you are talking _parrot-fashion_.

And do not forget that you must pay for all the knowledge you obtain,
whether you are rich or poor. Nobody else can pay for you. You, your own
self, must _pay attention_ with your own mind, through your own eyes and
ears, _or do without knowledge_.

Be wise: gain all the knowledge you can concerning everything worth
knowing, and use it for the good of yourself and other people.

"KNOWLEDGE IS POWER."



[Illustration: A, the heart; B, the lungs; light cross lines, arteries;
heavy lines, veins.]



PART I.

FORMULA FOR INTRODUCTORY LESSONS.

1. My body is built of bones covered with flesh and skin; the blood flows
through it, all the time, from my heart. I breathe through my nose and
mouth, and take the air into my lungs.

2. The parts of my body are the head, the trunk, the limbs.