INDEX 



19 



References are to pages 



Pulse 412 



Pupil (of eye) 414 



Radiation (of heat) .... 90 

 Rain . 104, 141, 170-174, 231-237, 



245 



Rainbow 359,365 



Rats (carriers of disease) . . 454 

 Reclamation (of soils) . . 332-338 



of alkali land 332-333 



of arid land 336-338 



of overflowed land . . . 338-339 



Reefs, sand 257-260 



Reflection (angle of) .... 352 



law of 352 



original rays of 352 



Refraction (of light) . 353-356, 364 



cause of 353-355 



effects of - . 355 



Relishes 431 



Reptiles (vertebrates) . . . 400 

 Repulsion (of magnets) . . . 476 

 Reservoirs ...... 172, 201 



for water-supply of cities . . 201 



lakes as 172 



Respiration ; see Breathing 



Retina (of eye) 414, 416 



Revolution (of earth) . 26-31, 39-40 



Rivers .... 176-208,546-548 



as inland waterways . . 190-196 



improvement of ... 192-196 



classes of .... 181-190, 207 



deltas . . 189-190, 207, 549 



drowned . . . 188-189,207 



intermittent 186 



meanders . 181-183, 187, 207 



terraced 186 



development of . . 177-181, 186, 



207 



graded 178-181 



old-age 186, 207 



young .... 177-178,207 



fall line of 547-548 



of coastal plains .... 546-547 

 Rocks . . . 252-255,275,279-281 



igneous 252-253, 275 



metamorphic . . . 254-255, 275 

 sedimentary . . . 253-254,275 

 weathering of .... 279-281 



Roemer on deductions as to 

 light 352-353 



Rolling (of soils) 327 



Roots (of plants) 366-373, 421-422 



as food 373 



functions of 373 



growth of 372-373 



rise of sap in 372 



structure of 372 



uses of 367-371 



Rotation (of earth) . . 23-26, 39 



effects of 24 



four cardinal directions . 24, 39 

 inclination of axis .... 26 



Run-off (of water) 174 



Saliva 420,433 



Salt 142, 425 



necessary for life-processes . 142 



solutions of 142 



Salt Lakes 172-173 



causes of 172 



fertility of beds of . . . . 173 

 Saltpeter (as fertilizer) . . . 316 

 Salts 54,58 



obtained by neutralization of 



acids and bases . . . 54, 58 

 San Francisco (earthquake and 



conflagration) 515 



Sand . . . 162, 281-285, 307-310, 

 319-320, 345, 549 



an agent in surface-changes 



281-285 



deposition of 283-285 



Sand blasts 281 



Sandstones (sedimentary rock) 



253-254 



Sandy soils .... 307, 319-320 

 Sanitation ; see Health and sanitation 

 Santa Ana (cyclonic storm) . . 229 



Sap (in plants) 372 



Saprophytes (dependents on 



dead animals and plants) . 397 



Sargasso seas 162, 532 



Sargassum (sea-plant) . . . 532 



Satellites ; see Moons 



Saturation 102-103, 104, 106, 112, 141 



in solutions 141 



in air 102-103, 104, 106, 112, 141 



