INDEX 



379 



Ice, 50, 116 



density of, 88 

 Images by reflection, 338-342 



how located, 340 

 Immune, 36-37 

 Incandescence, 18, 217-218 

 Industrial life, 281^-290 

 Industries, chemical, 188-192, 195, 

 199-203 



iron, 197-204 



petroleum, 284-287 



relation to coal supply, 196-199, 



216 



Inertia, 154 



Infection, 36-54, 61, 208, 236 

 Initiative, 2 43 

 Insects, 57-62, 278 

 Instinct, 277-278 

 Insurance, 235, 239 

 Intemperance, 66, 69 

 Ions, and ionization, 181-183, l86 > 



190 

 Iron (and steel), 197-204 



cast iron, 92, 201-202 



galvanized, 203 



pig iron, 201, 204 



properties of, 201-202 



tempering of (as steel), 203-204 



uses of, 196-197, 202-204 

 Irrigation, 105, 108, 244, 247 



K 



Kerosene, 17, 235, 286 

 Knowledge, 83-84, 210 



Labor, 281-284, 288-289, 292-295 



on farms, 327-328 

 Laws, of correlation of forces, 1 70 



of definite proportions, 16 



Laws, of gravitation, 155-156 



of life, 68 



of machines, 167 



of science, 98 



of "survival of the fittest," 265, 

 279 



of weather, 137 

 Leaves, 262, 264, 267, 270 

 Levers, 163-167 

 Life, 64-68, 71, 78, 356 

 Light, diffusion of, 179, 341 



in relation to heat, 217-218, 346 



phenomena of, 336-348 



reflection of, 339~34i, 344 



refraction of, 341, 343 



velocity of, 337 

 Lime, in water, 178-180 



for builder's uses, 191-192, 195 

 Liquids, 86 

 Literature, relation of to science, 



in, 242, 258, 364 

 Litmus, 180-182 

 Lumber, 255-256 

 Lungs, and their capacity, 22, 25 

 Lymph, 71-72 



M 



Machines, 163-164, 166-167, 169- 

 170, 196, 239, 284-285, 288, 



295 



for farm uses, 310, 327-331 



the human body as a machine, 



26, 29, 66 



Magnetism, 170-172 

 Malaria, 38, 6 1 

 Mammals, 305-306 

 Manhood, 81-83 

 Marble, 193-194 

 Mass, 152, 155-156 

 Matches, friction, 176 

 Matter, 151-158 



indestructibility of, 152 



living matter, 151-152 



properties of, 152-155 



