INDEX 



Questions, lists of 163, 168, 172, 180, 

 213-214, 232-233, 239-240, 

 247, 254, 259, 275, 280, 289- 

 290, 303-304, 307, 312, 3i7- 

 318,329-332, 348, 354-355 



Rainfall, 90-92, 94, 136, 138-139 



Rats, 61-63 



Recreation, 68-72 



Refrigeration, 118, 145 



Resistance, 154, 164, 167 



Respiration, 19, 24, in 



Rest, n, 66-72 



Revolution of earth, 148, 154, 157, 



351-355 



"leap year," 353 

 lengths of years, 353 

 velocity of, 353 

 Right living, 65-84, 207-208, 211- 



213 

 Rocks, 334-335 



limestone (see Gypsum), 192- 



196, 202 

 sandstone, 194 

 stratification of, 192-193 

 Roots, 243-244, 314 

 Rotation of earth, 128, 131, 349-351 

 rate of, 350-351 



"Safety first," 238-239 



Saliva, 6 



Sand, 247-248 



Sanitation, 46-51 



Schoolrooms, conditions in, 13-14, 



20-21, 23, 41 

 Schools, purposes of, 26, 42, 49, 51, 



68, 80-82, 84, 207, 2 1 1-2 1 2, 



252, 257, 292-296 

 Science, achievements of, 284, 289, 



295 



Seasons, 351-354 

 Seeds, 265-267 

 Serums, 37, 41, 45 

 Sewage, 56 



Shadows, 336-33?, 357 

 Sickness, 32-33, 35, 42, 57, 65, 74, 

 175 



by inheritance, 32 



treatment of, 33 

 Silos, 316 



Sleep, 19, 25, 32, 66-68, 72 

 Soap, 177-178, 19 



Social welfare, 41-43, 46-49, 61-62, 

 69-71, 74-75, 287-288, 290- 



295 



Soda, manufacture of, 190-191, 195 



Soils, 247-254, 332-335 



classes of, 247-248, 251, 332-333 

 fertility of, 251, 313 

 humus in, 251, 333 

 origin of, 333~335 

 sorting of by water, 333 

 temperature when water-soaked, 



96 



tillage of, 243, 246, 248-254 

 water content of, 248-249 



Solar heating, and obliquity of rays, 

 142-149 



Solar spectrum, 342-347 



Solids, 86, 98 



Solutions, 88-90, 98-99, 101 



Specific heat, 89, 146-147 



Spectrum analysis, 345-346 



Sports, 70 



Sprains, 3 



Sprays and spraying, 122, 321-323, 



325 



Standard time, 359-363 

 Starch, 222, 226 -229, 231, 317, 328 

 Stars, 366, 368-369 

 Sterilization, 45, 234, 236, 311 

 Stimulants, 72-99 

 Storage batteries, 120, 187 

 Strain (and stress), 154 



