What wonderful muscle moves without your will?--"The heart."

How does alcohol hurt the heart?--"It makes it beat too fast."

How does "beating too fast" hurt the heart?--"It makes it tired, and
sometimes wears it out." See Appendices on Alcohol and Tobacco.

* * * * *

[Illustration: THE SKIN (very highly magnified).--(From Walker's
_Physiology_, 1884.)]

A, arteries; V, veins; N, nerves; F, fat cells; E, the outer skin; CL, the
color layer; D, the true skin; PT, a perspiratory tube; HF, a hair and hair
sac; EP, muscles; SG, oil glands; TC, tactile corpuscles; CT, connective
tissue.

* * * * *

PART VII.

FORMULA FOR THE LESSON ON THE SKIN.

1. My skin covers my body.

2. It is thin, elastic, flexible, porous, and absorbent.

3. I have two skins; the inner skin is the true skin.

4. My true skin is elastic, and like a net-work of blood-vessels and