550 



INDEX 



Pa-pay-ans, 250 



changes of Bell-ans, 250 

 Parallel and series, 409 



wiring, 409 

 Parasite, 289 



Pasteurization of milk, 229 

 Peat, 164 

 Pegasus, 481 

 Penumbra, 326 



Peppermint test for soil pipes, 285 

 Pepper's ghost, 327 

 Percolator, 86 

 Phonograph, 432 



needles for, 433 



records for, 433 

 Photosynthesis, 186 

 Piano strings, 424, 425 



player, 430, 431 



where hammer strikes, 424 

 Pipe organ, 427, 428, 429, 430 

 Pisces, 483 

 Plane, incline, 496 

 Planets, table of, 474, 475 

 Plasma, 184 

 Pleiades, The, 480 

 Pneumonia, 300 

 Polaris, 479 

 Pollux, 483 

 Porosity, 445 

 Poisons in medicines, 247 

 Potato scab, 314 



blight, 314 

 Potential, 393 



Preparation of solutions, 539 

 Prest-o-lite, 162 

 Prism, refraction in, 333 

 Procyon, 484 

 Protein, 197, 183 



amount needed, 187 



as a fuel, 193 



excess of, 198 



sources of, 198, 203 



uses of, 203 

 Protozoa, 289 



Protozoa, disease caused by, 294 



Ptomaine poisoning, 307 



Ptyalin, 183, 221 



Pulleys, 494 



Pulp, 222 



Pumps, 40, 41 



Pupil, 355 



Putrefaction, from bacteria, 319 



Pyrene, 139 



Quarantine, 321 



Rabies, 297 

 Radiant energy, 88 

 Radiation, 87 



and the household, 89 



of dull and shiny objects, 



moisture and dust interfere with, 91 



questions on, 93 

 Radiometer, 91 

 Radium, 138 

 Rain, 34 

 Rainbow, 334 



Records, composition of, 433 

 Reflection, 327 

 Refraction, 332 



in plain glass, 332 



in prism, 332, 333 

 Refrigerators, circulation of air in, 107 



iceless, 7 



questions of, 97 



section of, 98 

 Regulus, 484 

 Resonance, 419 



sympathetic, 419 

 Respiration, 184 

 Retina, 344 

 Rigel, 484 



Rivers and streams, 284 

 Rochelle salts, in bread, 234, 235 



Saccharin, 242 

 test for, 242 

 Safety first, 504 



