Chapter XIII: Form Iv: Winter

Forest Trees 246
Evergreens; Wood Specimens 246

Fruits 247

Weeds and Weed Seeds 248

Physical Science Phase of Nature Study 248
Water Pressure--exercises 248
Study of Air 249
The barometer; the common pump; expansive
force of air; composition of air;
oxygen; carbon dioxide; impurities of air 250
Solutions of Solids 255
Solutions of Liquids 256
Solutions of Gases 256
Limestone 256
Carbon 257
Hydrogen 258
Magnets 258
Electricity 259
Steam 260
Farm tools--machines; problems 260