Garden Plants, xiii, 267-97; origin of, xiv, 382 Garfield, James A., speech of, xi, 323 Garnet Group, iii, 330 Gar Pikes, xii, 134, 152, 153 Garua, Peruvian fog, i, 95, 373 Gas Carbon, electrical conductivity, iv, 283 Gas Constant, iv, 142 Gas Engines, v, 155-6, 381; efficiency, on what dependent, iv, 192; ignition, vii, 369; in submarines, vi, 239; operation in automobile, vii, 123-33; starting of, vi, 235 Gases, adiabatic change in, iv, 158-9; atmospheric, i, 9-16; Boyle's Law, iv, 125-6, 133, 143; Boyle's and Mariotte's researches, xvi, 110; buoyant effect, iv, 30; Charles's Law, 140; chemical properties, viii, 297-8; combinations, Gay-Lussac's studies, xvi, 133; compressibility variations, iv, 143; condition at absolute zero, 142-3; conversion of liquids into, 152-3, 173-4; cooling by expansion, i, 30, 90; critical temperature, 29, iv, 171-3; diffusibility of, iv, 23, 131, viii, 22-3, 23, 108; distinguished by pressure and diffusibility, iv, 22-3; elasticity of, 158-9, 198; electric discharges through, 54-5, vii, 216, 301-2; electrolytic separation, 321-4; electrical conductivity of, iv, 259; expansion by heat, 135, 151; expansion coefficient, 145; flame due to burning, viii, 57; gram-molecular volume, viii, 109; heat absorption, 309; heat convection in, iv, 178; heat effects on, 139-40; heat from compression, i, 90, v, 351; heat non-conductivity, iv, 177, 178; ignition, viii, 54; interchanges of molecular energies, xvi, 134; ionization of molecules, i, 142, 143; isothermal changes in, iv, 156; latent heat of, 153, 173-4, v, 353, 354 (see Latent Heat); laws not inflexible, iv, 142-3; liquefaction of, 143, 153, 191-2 (see Liquefaction); Mariotte's law, 141; mechanical energy of, 142; molecular velocity in, 133; molecules in, iii, 309, iv, 22, 131, 132-3, 152-3, viii, 23, 24, 106, 305-6; molecules, number in, iv, 133, viii, 108-9, xvi, 133; monatomic, viii, 309; pressure of, v, 223, viii, 24-5, 109-10; pressure, to what due, iv, 30, 132-3; pressure, volume, and temperature laws, iv, 125-6, 139-43, v, 347, viii, 106-8; Regnault's constant, iv, 142; solidifying of, i, 32, iv, 153, 192; solubility in water, viii, 40, 111, 112; sound velocity in, iv, 155-6, 198, 199; specific heat ratio, 155-6, 159; spectra of, ii, 112-13, iv, 361-3; suspended change of state, viii, 113, 304, 305; vibration of, iv, 215; volume taken at atmospheric pressure, v, 223 Gas Lighting, vi, 195, 264; fire hazards, vii, 51 (see also Illuminating Gas) Gas Mantles, viii, 60, 252 Gasoline, combustion of, viii, 13, 52; explosiveness, vii, 124, viii, 23, 54, 62; production and uses, 208, 209, 235