442 



INDEX 



Foot pound, 44, 55 

 Force, 37 



centrifugal, 43 



muscular, 43 



gravitational, 43 



of expanding gases, 44 



of wind, 43, 68 



molecular, 45 

 Forests, 337 



Formaldehyde, 346, 348, 435 

 Friction, 63 



a source of heat, 126 

 Frogs, 359 

 Frost, 175 

 Fruits as food, 340 

 Fuels, 259, 266, 338 

 Fulcrum, 55 

 Fumigation, 434 



Fungi, 329-330, 342, 345, 348, 407 

 Fungicides, 348, appendix 

 Fusibility, 251 

 Fusion, 133 



Galactose, 392 

 Galileo, 37 

 Galvani, 200 

 Garbage, 418 

 Gas, 242 



artificial, 243, 262 



natural, 243, 263 



acetylene, 244 

 Gases, 26, 255 

 Gelatin, 388 

 Gelatin cultures, 409 

 Germination, 320 

 Germs, 408, 410 

 Glaciated soil, 285 

 Glass, 240 

 Glucoses, 392 

 Gluten, 388 

 Glycogen, 392 

 Gold, 255 

 Gram, 39 



Gravitation, 17, 37 

 Ground water, 299-300, 310 

 Guncotton, 274 



Hail, 178 



Health, 240, 406-436 

 Hearing, 216, 218 

 Heat, 126, 202, 220, 247 



a form of energy, 126 



sources of, 126, 259 



effects of, 130 



Heat Cont. 



quantity of, 137 



capacity, 137 



of fusion, 138 



conduction of, 140 



from electric current, 202 

 Heating systems, 147-148, 202, 266 

 Hercules, 10 

 Hessian fly, 367 

 Horse latitudes, 164 

 Horse power, 44, 65 

 Humidity, 151, 173 

 Humus, 284, 292 

 Hurricanes, 166 

 Hydra, 353 

 Hydraulic press, 114 

 Hydrocarbons, 259, 262 

 Hydrochloric acid, 273 

 Hydrogen, 94-97, 272, 274 



Ice, 100, 108-109 



Igneous rock, 281 



Incandescent bodies, 220 



Incandescent lamps, 203 



Incandescent mantles, 243, 263 



Incidence, angle of, 225 



Inclined plane, 53, 61 



Incubation, period of, 410 



Inertia, 42 



Inland seas, 302 



Insects, 355, 356, 365, 368, 428 



Insulators, 193 



Invertebrates, 358 



Iris, 236 



Iron, 251 



Irrigation, 297, 310-314 



Irritability, 315 



Isobars, 154 



Isogonic lines, 190 



Isotherms, 158 



Jack screw, 62 

 Jupiter, 2, 3 



Kerosene, 242, 264 

 Kilogram, 32 

 Kindling point, 264 

 Kinetic energy, 41 

 Koch, Robert, 409 



Lachrymal fluid, 235 

 Lactose, 393 

 Lakes, 302, 303 

 Lamps, 143, 242 



