The Science of Everyday Life: Projects for Junior High Schools

Front matter

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Part I. The Chief Necessities of Life Introduction

UNIT I. THE AIR AND HOW WE USE IT

PROJECT I. THE AIR A REAL SUBSTANCE Introduction

Air is real.

Problems

Three forms of matter, 8. The atmosphere an ocean of air, 9. Aii pressure, 10. Making a mercurial barometer, 10. The barometer usee to indicate height, 10. The aneroid barometer, 11. The barometei used to forecast weather, 12. Air pressure and the suction pump, 12 The force pump, 12. Air pressure and the exhaust pump, 12. Th< bicycle pump, 13. Air pressure and the action of the siphon, 13. Prea sure on the human body, 1 3. Structure of the human ear, 14. Air trans mits sound, 15. The nature of sound, 16. The rate at which sounc travels, 16. Compressed air, 17. Liquid air, 17. Balloons, 18. Air planes, 19.

PROJECT II. AIR AND FIRE

Fire in its relation to our lives.

A fire needs air, 26. Composition of the air, 26. Burning decreases the amount of oxygen, 27. Extinguishing fires, 27. Burning often increases the amount of carbon dioxide and water in the air, 27. Elements and compounds, 28. Compounds are different from the elements composing them, 28. Elements may combine with each other 29. Oxidation, 30. Kinds of oxidation, 30. Slow oxidation, 30. Ox-

CONTENTS

n helps us work, 31. Matches, 31. Matter may change its form annot be destroyed, 32. Matter cannot be created, 33.

DUAL Projects 33

PROJECT III. AIR AND BREATHING

tODUCTION 34

11 plants and animals breathe.

DBLEMS 34

>pics:

Activity in relation to the rate of breathing, 40. Heat production in relation to the rate of breathing, 40. Air that we breathe in, 41 . Air that we breathe out, 41. Breathing of plants, 42. The human body a machine, 42. Cells, the building units of the living body, 42. Parts of a cell, 43. How many cells a living body contains, 43. Tissues and organs, 44. Cells in the blood, 44. The breathing organs of the human body, 45. Why the air passes into and out of the lungs, 45. The value of deep breathipg, 46. Oxidation in the cells of the body, 46. What becomes of the waste matter, 46. Artificial respiration, 47.

PROJECT IV. AIR AND HEALTH

Fresh air.

Problems

Factors which control ventilation, 54. Temperature of air, 54. Amount of water vapor in the air, 54. Foreign material in the air, 55. Cleaning and dusting, 55. Air and disease, 56. Enemies of health, 56. How bacteria enter the body, 57. How bacteria attack the body, 57. How bacteria increase in numbers, 58. How the body defends itsel^ against the attacks of bacteria, 58. The external defenses, 59. Th internal defenses, 59. The antitoxin treatment for diphtheria, 6c Bacteria present in healthy people, 61. Importance of keeping tl body in a healthy condition, 61. How to keep well, 62. Effects alcohol and tobacco, 62. Seasons in relation to prevalence of dise 63. Some ways in which bacteria are spread, 63. How to care the sick, 65. Antiseptics and germicides, 65. What the commu ^'*n do to prevent illness, 66.

CONTENTS ix

UNIT IL WATER AND HOW WE USE IT

PROJECT V. WATER IN OUR HOUSES Introduction 68

Water a necessity of life.

The human body needs water.

Sources of our drinking-water, 78. Pure water and impure, 79. Typhoid fever, a disease often spread by impure drinking-water, 79. How water is purified, 80. Water pressure, 82. Water supply systems, 83. A house piping system, 86. A hot-water heater, 86. Waste pipes of the house, 87. Sewage disposal, 88. Water changes from one form to another: the physical states, 89. Water freezes to ice, 89. Water changes to vapor, 90. Water changes to steam, 90. Cooking food by boiling, 90. Changes produced in food by boiling, 91. Water as a solvent, 92. Hard and soft water, 93.

PROJECT VI. WATER IN THE AIR

The weather.

Water in an invisible form in the air, 105. How the water vapor gets into the air, 105. Where the water vapor comes from, 106. Evaporation from plants, 106. The thermometer, 106. Temperature and the amount of water vapor in the air, 108. Humidity of the air, 108. Condensation, 109. Kinds of clouds, 109. Thunderstorms, 109. Dew and its formation, no. The wind, no. Winds of the world, 112. Foretelling a storm, 113. The path of storms, 115. The Weather Bureau, 115. The value of rain, 116.

PROJECT Vn. WATER AND THE SOIL Introduction 119

How soil is made.

The value of water in the soil.

X CONTENTS

What soil contains, 125. Rocks, 125. Igneous rocks, 125. Sedimentary rocks, 126. Metamorphic rocks, 127. The action of water in making soil, 127. The action of ice, 130. The action of wind, 131. The action of air, 131. The action of plants, 132. The action of animals, 132. Plants need water, 133. Water in the soil, 133. How water rises in the soil, 134. How to save the moisture in the soil, 135. Variation in the amount of rainfall, 136. Reclaiming desert regions, 136. Air in the soil, 137. Reclaiming swampy regions, 137. Acid soil and how to correct it, 138.

UNIT III. FOODS AND HOW WE USE THEM

PROJECT VIII. PLANTS — FOOD-MAKERS FOR THE

WORLD

Foods — a necessity of life.

Food conservation.

Where our foods come from, 152. Organic and inorganic foods, 152. The nutrients, 153. Physical and chemical changes, 153. Where do plants get their food? 154. The organs of a plant, 154. Root- hairs, 155. How a root-hair absorbs soil water, 155. How water passes through a plant, 156. Where foods are manufactured, 157. The raw materials needed, 157. Starch is made only in green plants, 158. The sun furnishes the necessary energy, 159. The waste product is oxygen, 159. Leaves make all the organic nutrients, 159. Helping plants make foods, 159. Nitrogen-fixing bacteria, 160. Electricity as a means of taking nitrogen out of the air, 161. Home gardens, 161.

PROJECT IX. FOODS AND THE HUMAN BODY

Introduction • .

The two great uses of foods.

How to select foods, 167. The amount of nourishment in foods, 167. Meaning of the term "Calorie," 168. A mixed diet usually desirable, 168. People need varying amounts and kinds of food, 169. A food table, 170.

CONTENTS

Food charts, 172. The cost of foods, 179. Taste and digestibility, 179. Quality and cleanliness, 179. Tea, coffee, and other food adjuncts, 180. Why we cook foods, 1 80. The value of some uncooked foods, 1 80. The food tube, 180. Digestion and its use, 181. Digestion in the mouth, 182. Stomach and intestinal digestion, 182. The circulation of blood, 182. Kinds of blood vessels, 183. Treatment of cuts, 183. Stomachaches, 184. Headaches, 184. Teeth and their care, 184. Structure of a tooth, 185. Cavities in teeth, 185. How to care for the teeth, 186. The effects of alcohol and tobacco upon digestion and circulation, 186.

Individual Projects , . li

PROJECT X. FOODS IN THE HOME

Introduction i{

Clean foods.

Problems . . . . . iJ

Why foods spoil, 196. Comparison of bacteria, molds, and yeasts, 196. The action of bacteria on food, 196. The action of molds on food, 197. How to avoid molds, 197. The action of yeast on food, 198. Yeast as a foe, 199. Yeast as a friend — breadmaking, 199. How to protect foods against molds, and harmful bacteria and yeasts, 199. The cold pack method of canning, 200. Drying foods, 201. Pure milk, 201. Pasteurized milk, 202. Cuts of meat, 203. Dangers in meat, 204. Cleanliness in the kitchen, 204. The work of a city health department, 205. Pure food and drug laws, 205.

Individual Projects 2C