37

V.--BEER 43

VI.--DISTILLING 47

VII.--ALCOHOL 50

VIII.--TOBACCO 53

IX.--OPIUM 59

X.--WHAT ARE ORGANS? 61

XI.--WHAT DOES THE BODY NEED FOR FOOD? 71

XII.--HOW FOOD BECOMES PART OF THE BODY 79

XIII.--STRENGTH 85

XIV.--THE HEART 93

XV.--THE LUNGS 97

XVI.--THE SKIN 103

XVII.--THE SENSES 109

XVIII.--HEAT AND COLD 115

XIX.--WASTED MONEY 122

CHAPTER I.

JOINTS AND BONES.

[Illustration: L]ITTLE girls like a jointed doll to play with, because
they can bend such a doll in eight or ten places, make it stand or sit,
or can even play that it is walking.

[Illustration: _Jointed dolls._]

As you study your own bodies to-day, you will find that you each have
better joints than any dolls that can be bought at a toy shop.

HINGE-JOINTS.

Some of your joints work like the hinges of a door, and these are called
hinge-joints.

You can find them in your elbows, knees, fingers, and toes.

How many hinge-joints can you find?

Think how many hinges must be used by the boy who takes off his hat and
makes a polite bow to his teacher, when she meets him on the street.

How many hinges do you use in running up-stairs, opening the door,
buttoning your coat or your boots, playing ball or digging in your
garden?

You see that we use these hinges nearly all the time. We could not do
without them.

BALL AND SOCKET JOINTS.

All our joints are not hinge-joints.

Your shoulder has a joint that lets your arm swing round and round, as
well as move up and down.

Your hip has another that lets your leg move in much the same way.

[Illustration: _The hip-joint._]

This kind of joint is the round end or ball of a long bone, which moves
in a hole, called a socket.

Your joints do not creak or get out of order, as those of doors and
gates sometimes do. A soft, smooth fluid, much like the white of an egg,
keeps them moist and makes them work easily.

BONES.

What parts of our bodies are jointed together so nicely? Our bones.

How many bones have w