INDEX 



477 



Focus, 46, 159 



Fogs, 86, 237 



Food, 347, 353, 361, 363, 366, 431 



and body heat, 71 

 Foot, 7 

 Force, 21, 24 



centrifugal, 27 



buoyant, 33 

 Forest, 275, 307 

 Formaldehyde, 454 

 Fossils, 259 



Franklin, Benjamin, 133 

 Freezing mixtures, 89 

 Friction, 24. 182 



electric charges by, 130 



and heat, 73 

 Frog, 327 

 Frost, 91, 236 

 Fruits, 299, 307 

 Fuels, 72 

 Fumigation, 429 

 Fungi, 301, 303 

 Furnace, hot air, 64 

 Fuse, 228 



Galileo, 20, 39 

 Gall, 358 

 Galvani, 136 

 Gang plows, 273 

 Ganglia, 397 

 Gas, carbon, 112 



illuminating, 225 



for lighting, 224. 

 Gases, 54, 68 



collection of, 45 



expanding, 22 



liquefying of, 68 



properties of, 67 

 Gas meter, 226 

 Gasoline, 115, 214 



engine, 23 



and kerosene stoves, 213 

 Gas-pipes and fixtures, 225, 226 

 Gastric juice, 189, 351, 356 

 Germs, 303, 428, 437, 447 

 Gills, 52, 319, 325 

 Glacial drift, 268 



period, 268 



soil, 270 



Glands, 350, 357, 376, 417 

 Glass, 43, 221, 222, 223 

 Glucose, 349 

 Gluten, 348 

 Glycerine, 199, 366 

 Glycogen, 358, 362 

 Granite, 259, 261, 263 

 Graphite, 5, 110, 142 

 Gravitation, 18 

 Gravity, 17, 18, 22, 29, 268 

 Gravity cell, 137 

 Gray, Elisha, 171 

 Gun cotton, 54 

 Gunpowder, 22, 54, 210 

 Gymnosperms, 291, 305 

 Gypsum, 279 



Habit, 405 

 Hail, 240 

 Hair, 389 

 Halo, 161 



Hardness of water, 79 

 Harvey, 372 

 Hearing, 409, 413 

 Heart, 373, 374 

 Heat, 52, 59, 62, 136 



capacity, 70 



sources of, 72 



use of, by the body, 71, 347 

 Heating, 214 



of air, 234 



hot water and steam, 214 



systems, 220 

 Hemoglobin, 377 

 Hinge joint, 341 

 Hornblende, 259 

 Horse-power, 25 

 Human body, 338 

 Humerus, 344 

 Humidity, 220, 221, 236 

 Humor, aqueous, 416 

 Humus, 269 

 Hunger, 410 

 Hurricanes, 249 

 Hydra, 314 



Hydrants and traps, 209 

 Hydrocarbons, 114 

 Hydrochloric acid, 105, 189 

 Hydrogen, 95, 96, 98, 99, 103 



