Carbonate of Lime, ancient layers of, iii, 250, 251; animal shells and skeletons of, 259, 266, 267, 268, 270; hard water due to, 126; limestone composed of, 25, 308; in sandstone, 27 (see also Calcite, Calcium Carbonate, Limestone) Carbonates, formation of, viii, 49; in blood, x, 280; metal compounds, viii, 130, 147, 198; metal extraction from, 131, 271; test of, 290 Carbon Compounds, viii, 42, 48-52, 61; optical activity, xvi, 164 Carbon Cycle, viii, 49-50, 325-6, 334-5, 349-50 Carbon Dioxide, viii, 42, 48-50; atmospheric, i, 10, 11, 13-14, 25, 322, viii, 48, 49, 67-8, 152, ix, 26, 254; body production and elimination, ix, 190, 248, 253-4, 262-7, 268, x, 270, 280, 281, 338, 339; boiling and freezing points, iv, 173; critical temperature and pressure, 172, 173; fatigue product, xi, 270-2; in blood, ix, 263, 264-7, x, 331, 339; in blood, loss in mountain sickness, i, 328; in Carbon cycle, viii, 334, 350; in limestone, 42, 49, 152; in minerals, 201; in water, 40, 111; leavening agent, 50, 136, 137; plant uses of, 219, 335, 347, 349, ix, 26-7, xiii, 80-1, 82, xiv, 65; product of combustion and decay, viii, 12-13, 26, 45, 61, ix, 26, 190; produced by fermentation, 248; production, commercial, viii, 48, 276; rock disintegration by, 194-5; thrown off by lungs, 353; vitiation of air by, 331, 332, ix, 268, x, 238 (see also Carbonic Acid) Carbon Disulphide, combustion of, viii, 61; light refraction by, iv, 331; refrigeration by, 174 Carbonic Acid, viii, 48-9, 101, 115; atmospheric content affected by light, x, 253; chemical action on rocks, iii, 24, 25, 27, viii, 194; critical temperature and pressure, iv, 172; early studies, xvi, 119-20; elimination in sleep, xi, 283; formation in body, x, 280; heat absorption by, iii, 248; in ground waters, xiv, 142, 146; in sea water, iii, 54; in sodium compounds, viii, 134-6; in urea, 230, x, 279, viii, 61; light refraction by, iv, 331; refrigeration by, 174 Carboniferous Period, iii, 197; animals of, xv, 71; landscape of, xiii, 320; length and antiquity, 314, 322; plants of, 307-11, 315-17 Carbon Monoxide, viii, 50-1, 157 Carbon Tetrachloride, vi, 101, viii, 212 Carborundum, chemical composition, 90; discovery, manufacture, and uses, vii, 300, 301, 309-11, xvi, 190; refractory, vii, 308, 311; in wireless detectors, 269 Carboxyl Group, viii, 220, 375 Carbuncles, cause of, x, 195, 311 Carburetors, vii, 124-8; mixtures in, v, 156 Caribbean Sea, hurricane reports, i, 282, 309 Caribe (fish), xii, 159-60 Caribou, xii, 320; horns of, 316 Carlsbad, Bohemia, xiv, 145, 152 Carlyle, dyspepsia of, xi, 369; on work, 276; on shame and clothing, x, 306 "Carnegie," magnetic survey ship, i, 193, vi, 39 Carnelian, iii, 337