432 



Pineapples, 350, 351 



Pistil, 347 



Planets, 410 



Plants, 335, 352, 361, 367, 368, 373 



Polarization, 254, 255 



Pollen, 347 



Pollination, 348 



Pond scum, 369 



Potassium chlorate, 47, 51 



Potatoes, 362 



Potential, 251, 253 



Power, 196 



Pressure, 148 



Primitive man, 100, 404 



Protein, 118 



Protoplasm, 339 



Protozoa, 381 



Pruning, 357 



Pulleys, loo 



Pumping system, 228 



Pumps, 213 



Pupil of eye, 279 



Purifying water, 138, 226 



Radiation, 95 

 Rain, 157 

 Rainbow, 274 

 Rat, 400 



Refrigeration, 168, 423 

 Reptiles, 390 

 Reservoir, 230 

 Retina, 280 

 Rice, 363 



Right-hand rule, 259 

 Rock, 308 

 Roots, 338, 352 

 Ropes, 365 

 Rusts, 373 



Salts, 20, 94 



San Jose scale, 377 



Saprophytes, 370 



Screw, 189 



Seeds, 335, 352 



Shooting stars, 412 



Siphon, 213 



Smokers, 43 



Snakes, 300 



Snow, 98, 157 



Soap, 16, 17, 18 



Soft drinks, 40 



Soil, 305; care of, 321 



Solid, 65 



Solvent, 140 



INDEX 



Soothing sirups, 45 



Sound, 294 



Specific heat, 77, 78 



Spectrum, 274 



Spirogyra, 369 



Spontaneous combustion, 50 



Spores, 35, 369, 374 



Stamens, 347 



Standpipe, 229 



Starch, 115 



Stars, 411 



Steam, n, 104; engines, 207; gauge, 



164; heating, 104 

 Stems of plants, 340 

 Stigma, 347 

 Stimulants, 40, 41 

 Stomach, 7, 103 

 Stomata, 344 

 Stove for heating, 101 

 Style of flowers, 347 

 Success, 6 



Sugar, 54, 115; cane, 362 

 Sulphur, 36, 37 

 Sun, 408 



Tapeworm, 401 

 Tea, 40, 41 

 Telegraph, 262 

 Telephone, 268, 270 

 Temperature, 76 

 Theine, 41 

 Theobromine, 41 

 Thermometers, 72 

 Thermos bottle, no 

 Tinder, 51 

 Toad, 389 

 Tobacco, 42. 62 

 Transformer, electrical, 266 

 Transplanting, 357 

 Trees, 357, 359 

 Trichina, 402 

 Turbine wheel, 202 

 Twines, 365 



Undershot wheel, 201 



Vacuole, 381, 383 

 Varnish, 39 

 Ventilation, 63, 100 

 Vibrations, 295 

 Vision, 281 

 Vitreous humor, 280 

 Vocal cords, 300 



