400 



ELEMENTS OF GENERAL SCIENCE 



preservatives in, 859-860 ; purpose 

 of, 337; sources of, 76-76; stor- 

 age of, 333 ; transfer of, 330-331 ; 

 transportation of, to the cells, 340 ; 

 use of, by plants, 334 ; utilized by 

 animals, *336-366; where used, 

 330; and work, 342-343 



Food groups, *346-350 



Foods, kinds of, 829 ; proper balance 

 of, 345 



Football, 3, 8 



Foot-pound, 181 



Ford automobile, 188* 



Forecasting weather, 56 



Forest Service, the United States, 163 



Forests and drainage, *304-308 ; and 

 erosion, 304-308 



Formaldehyde, 94 



Formalin, 359 



Fort Dearborn, location of, 166 



Fox, overproduction of the, 382 



Freezing, 113, 114, 118, 126, 127 



Freezing mixtures, 126-127 



Freezing point, 119 



Freezing water, work by, 281* 



Friction, 178; produces heat, 185 



Frog, development of, *366-368 



Frost warnings, 66 



Fruits, drying of, 96; and climate, 

 160-151 



Furnaces, 18 



Fuse wire, 197 



Fuses, *197-199 



Galaxy, 278 



Galileo, 257 



Galveston, hurricane in, 49* 



Gas in candle flame, 64*, 65*, 70, 71 ; 



pressure, 61 

 Gases, diffusion of, 69 ; expansion of, 



58 ; mixtures of, 61 

 Gasoline, 140 

 Gelatin, 89, 90 

 Gemini, 273 



Generator for carbon dioxide, 72* 

 Geological Survey, the United 



States, 303 



Germ diseases, 100-112 

 German silver wire, 197 

 Glaciers, *283-286 

 Glass, 140 

 Gold, 69, 140 

 Grafting, 373 



Grand Haven, temperature of, 1 43 

 Grasslands, *319-320 



Gravel, 288, 290 :: 



Grazing, 319-320* 



Great Bear, 272 



Great Dog, 273 



Great Lakes, climate near, 160-151 ; 



transportation on, 154-165 

 Greenhouse, 33 

 Guard cells, 79 



Haemoglobin, 342, 344 



Halley's comet, 262* 



Harbors, 168 



Havana, Cuba, healthf ulness of, 107- 

 108 



Heart and circulation, 340, 341*, 342 



Heat, as energy, 185; and mechanical 

 energy, *183-194; and molecular 

 movement, 61 



Heat and light from electric cur- 

 rents, *195-216 



Heating of land and water, *146-147 



Hercules, 278 



Heredity, 394 



Hereford, *386-388 



High-pressure centers, *39-49 



Hot waves, 47 



House fly, carrying of bacteria by, 

 105, 106, 107*; disposal of, 106*; 

 life history of, 105*, 106* 



Human body a machine, 337 



Humidity, absolute, 24-31 ; in cy- 

 clones, 45, 46 ; in houses, 80 ; rela- 

 tive, 24-31 ; variations in, 29 



Humus, 291, 306 



Hurricanes, 48, 49* 



Hybrids, 385-386, 388* 



Hydraulic press, *183-136 



Hydrochloric acid, 72 



Hydrogen, 66, 67, 69, 119, 268, 291 



Hydrometer, 222* 



Hygienic aspects of nutrition, 356- 

 362 



Hygienic conditions, 102, 108 



Ice, 113-127, 140 



Ice cream, 127 



Ice machines, 122-123* 



Illinois and Michigan Canal, 168 



Incandescent lamps, 213* ; 240 



Indian pipe, 83* 



Individuals, differences in, 383 



Industries, electrical, 241-242 



Influenza, 95 



Inheritance, 393-394 



Insulators, 199 



