490 



INDEX 



Opium, 192 

 Ore, 173, 215 

 Organ pipes, 286 

 Osmosis, 439 

 Ovary, 425 

 Ovules, 425, 427 

 Oxalic acid, 170 

 Oxidation, 50-54 

 Oxygen, combustion, 50 



component of water, 344 



in air, 385 



in bleaching, 161 



plant life, 59-60, 444 



preparation of, 50-51 

 Oysters, 470-471 



Paint, 183-184 



mixing, 274 



prevents rust, 54 



removal of stains, 146-147 

 Pancreatic juice, 95 

 Paper making, 139 

 Paraffin, 126 

 Parasite, 442 

 Parks, public, 4\\ 

 Patent medicines, 193-195 

 Peat, 119 

 Pepsin, 93 

 Petroleum, 124-128 

 Pewter, 179 

 Phosphoric acid, 102 

 Phosphorus, in fertilizer, 188 



in matches, 51-53 



sources of, 189 



Photography, 257-258, 263-267 

 Piano, 284, 285 

 Pig, 462 

 Pig iron, 175 

 Pigments, 184, 274 

 Pikes Peak, 405, 410 

 Pineapple, chemical substitute for, IO2 

 Pistil, 424-425 

 Pith of stems, 450-451 

 Plane, inclined, 297-300 

 Plants, and sand dunes, 391 



Plants, as protection against erosion, 



375-376 



carbon dioxide, used by, 59-60, 440- 

 441 



cultivated, 433-434 



desert, 350-352 



effect of light upon, 268-269 



effect of water upon, 34.8-352 



food of, 186-187 



wild, 43 3 



working, 430-442 

 Plateaus, 407 

 Pneumatic tubes, 333 

 Poisonous plants, 449-450 

 Polar regions, 394-396, 398 

 Poles, of earth, 396-397 



of magnet, 226-228 

 Pollen, 424-427 

 Pollination, 426-427 

 Pompeii, 413 

 Potash, 189-190 

 Potassium, 181 



chlorate, 50-51 



permanganate, 159 

 Potato beetle, 477 

 Poultry, 463-465 

 Prairie, 348, 350 

 Precipitates, 361362 

 Preservation of food, no-'f? 

 Pressure, of air, 32.1, 378-379 



of water, 335~339 

 Printed fabrics, 171-172 

 Printing, 176, 215-216 

 Prisms, 254 

 Proteins, 71-72 



effect of heat upon, 82-83 

 Prussian blue, 165 

 Ptomaine poison, 109-110 

 Ptyalin, 92, 93 

 Public health, 202-206, 444 

 Pulleys, 302-304 

 Pumice, 418 

 Pumps, 319-333 

 Pupa, 474, 475, 477 

 Pure Food Laws, 99, 102, 104, 117 



