Ingersoll, Dr. E., author Zoölogy, Vol. xii Ingots, steel, v, 322; "pipes" in, 323 Injections, subcutaneous, ix, 59 Injectors, of boilers, v, 140-2, 380 Ink, Acheson's, vii, 301 Innominate Bone, ix, 63 (fig.), 66-7 Inoculation, early practice of, x, 207; for anthrax and rabies, 141-2; for smallpox, 100-3 (see also Vaccination) Inorganic, defined, viii, 378 Inorganic Chemical Industries, viii, 267-84 Inorganic Compounds, colors of, viii, 312; solubility in water, 37, 111-12 Inorganic Matter, plant use of, viii, 339, 349, xiii, 14, 79, 81 Inorganic Nature, chemical inactivity, viii, 267 Insanity, definition and symptoms, x, 357-9; former ideas and treatment, 11, 356-7; increase of, xv, 27; increase prevention, x, 235-6; Pinel's treatment, 110-11; primitive conceptions of, xv, 350, 353 Insecticides, arsenic, viii, 169 Insectivora, xii, 366-8; lemurs and, 376 Insects, xii, 99-126; capture of, by plants, xiii, 39-41; classification, iii, 260, 276; cold effects on, ix, 306; evolution, iii, 20, 257, 279, xii, 104-7; flower fertilization by, xiii, 48, 123-46, 318, xvi, 152-3; fossil remains, iii, 16, 279-80; hearing of sounds by, iv, 204; jaws in, xii, 106; larvæ affected by light, x, 253; musical, xii, 109-10; number of species, 99; popular definition, 90; primitive groups, 104-7; protective coloration in, xv, 17-18; reproduction in, xii, 104; respiration in, 103; structure of, 99-103; studies of, xvi, 143-4; tool-using by, v, 10-11 Inside Passage, xiv, 258-9 Insomnia, xi, 288-91; caused by vasoconstrictor activity, ix, 218-19; exhaustion from, xi, 59-60 Inspiration, as intuition, xi, 245; Titchener on, 226 Instincts, defined, xi, 46-8; fundamental, 49-56, xv, 185; in man and animals, 65-6; reflex nature, xi, 48-9; self-preserving, x, 9-10, 282-3 Instrument-Shelter, i, 375 Instrument Transformers, vii, 44, 165 Insular Climate, xiv, 347 Insulation, importance, vi, 9-10; in dynamos, 192, 211-12; types of wire, vii, 58 Insulators, electrical, iv, 259, vi, 294-5, vii, 370; pin and suspension types, 15-16 Insulators, heat, iv, 178, vii, 307-8 Insults, emotions from, xi, 150 Insurance, weather, i, 269-70, 344 Intake-Output Test, x, 379 Intellectual Processes, in brain, ix, 147-53, 154 Intelligence, artificial selection of, xvi, 154; mental economy and, xi, 377; instinct and, 46, 47, 50; nervous organization and, 13 Intelligence Tests, xi, 359-60 Intemperance, arteries injured by, ix, 214 Intensity, electric, vii, 370 Intensity, of sounds, iv, 211 Interborough Rapid Transit Company, great alternators, vi, 216, 378-9; synchronized plants, 384 Interchangeable System, v, 48-52, 53-4, 55-6