Explosives, viii, 63, 260-2; detonation, 262; history of development, xvi, 163; nitrogen compounds in, viii, 66, 71-2, 74, 75, 237, 253, xiv, 66; nitrogen waste in, viii, 345-6; sulphuric acid in, 80; weather making by, i, 335-9 Exposure (outcrop), iii, 381 Extemporaneous Speeches, xi, 245 Extension, perception of, xi, 166, 171-2, 183-9 Extensor Muscles, ix, 76-7, xi, 54, 166 Exteroceptive Senses, xi, 63 Extrusive Rocks, xiv, 105 Eye-and-ear Method (astronomy), xi, 155 Eyeglasses, benefits of, iv, 51 (see also Glasses) Eye-mindedness, xi, 222 Eye of the Storm, i, 136, 372 Eyes, vi, 270-3, ix, 109-11, xi, 83-97; abuse of, mental effects, 373-4; color, inheritance of, ix, 335-6; color in different races, xv, 37, xvi, 48, 49, 50; color perception by, ix, 116-17; color perception limits, iv, 360-1; comparable with camera, ix, 108; connection with brain, 124, 142; controlling nerves, xi, 30; depth perception by, ix, 120; diseases and defects, 112-14; distance of distinct vision, iv, 342, 343; distance perception by, ix, 118-19; double images, xi, 175-81; fatigue from, 279; fear effects, 132; fixation, how learned, 39-40; inflammation due to lack of vitamines, x, 260; in infants, ix, 350, 351, xi, 39, xv, 61; in sleep, xi, 282, 283, 286; muscles around, ix, 77; of various animal forms, xii, 67, 101-2, 138-9, 205-6, 209; origin, xi, 109; persistence of vision, iv, 346-7; position in attention, xi, 232; pupil size, iv, 343; receptor organs, xi, 30, 62; regulation to light, x, 254; sensibility to light waves, iv, 360; smooth muscles of, ix, 161-2; soul in, savage idea of, xv, 330-1; space perception by, xi, 169-70, 171-2, 173, 174-83, 186-90; winking and watering of, 19, 23, 63 (see also Sight, Vision) Eye Sockets, ix, 62 Eyestrain, ix, 113, 114, 239; Behan on, xi, 374 Eyra, xii, 364 Fabre, J. H., xvi, 143-4 Fabrics, making of, v, 268-88; manufacturing processes, viii, 256; Philippine fiber, xiii, 236, 239; warmth of different, ix, 311-12, x, 309 Fabry, Wilhelm, x, 78-9 Face, anthropological measurements, xv, 43-5; brain case and, 43, 62; in infants, ix, 345; pallor and flushing of, 161, 165, 166; brain power expressed in, xv, 39, 63-4; color in different lights, iv, 364-5; painting of, xv, 256 Facial Angle, xv, 44-5 Facial Expressions, xv, 63-4; dejection and, xi, 337, 339; man's trained control, 82, 350-1; smell and, 82; smiling, 357; taste and, 74, 75, 76; tone of voice and, xv, 144 Factor Differences, xiii, 330, 331-2