A few years hence, when the results of this study in our Normal Schools shall be realized in the preparation of the teacher, we can depend upon her adapting oral lessons from advanced works on this theme, but now, the average primary teacher brings to this study no experience, and limited previous study. To meet this need, this work has been prepared. Technical terms have been avoided, and only such facts of physiology developed as are necessary to the treatment of the effects of alcohol, tobacco, opium, and other truths of hygiene. To the children in the Primary Schools of this country, for whom it was prepared, this work is dedicated. [Illustration] CONTENTS CHAPTER PAGE FRONTISPIECE 2 TITLE-PAGE 3 PREFACE 5 CONTENTS 7 I.--JOINTS AND BONES 9 II.--MUSCLES 19 III.--NERVES 25 IV.--WHAT IS ALCOHOL? 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.