Copper, affinity intensity, viii, 128, 164; alloys, 164, 171, 273; atomic weight and symbol, 383; density of, iv, 113; electrical conductivity, iv, 283, vi, 77, 79, 80, viii, 164; electrical positiveness, vi, 59; electric welding of, iv, 312; electrochemical analysis, viii, 295; extraction methods, 270-1; fungicide uses, 170; formerly mined in New Jersey, xiv, 112; heat conductivity, iv, 176, 179; melting point and requirements, 162, viii, 384; name, origin of, xv, 157; native, iii, 327; occurrence and production, 360-2, viii, 129, 130-1, 163, 198, xiv, 237, 288; refining of, vii, 319-20, viii, 166-7, 272; specific heat of, iv, 155; specific gravity, viii, 384; tests for, 286, 287, 288; uses, iii, 359-60, viii, 126-7, 163-4, 167; valences of, 94, 189 Copper Bromide, color, viii, 123 Copper Chloride, color, viii, 123; electrolysis of, 124 Copperhead Snakes, xii, 233 Copper-Plating, vii, 314-15, 317-18, viii, 165-6 Copper Pyrites, iii, 326 Copper Smelting, smoke precipitation, vii, 347 Copper Sulphate, color, viii, 123; electrolysis of, 125; uses, 146, 332; used in Egyptian medicine, x, 12; water and, mixture of, iv, 131 Copper Wire, for electrical transmission, vi, 77, 79, 80, vii, 20, 22-3, 104; standard tables, 378-80; table of carrying capacities, 381 Copra, xiii, 220, xv, 125 Coquina Rock, viii, 152 Coral Reefs, xii, 40-2, xiv, 263-4; formed in shallow water, iii, 53, xiv, 276; oceanic islands built of, 276, 277; temperature limitations, 263-4, 305, xii, 40 Corals, iii, 259, 266, 267-8, xii, 38-43; calcium carbonate in, viii, 151; false, xii, 47 Coral Snakes, xii, 213, 225-6 Corbeil, Gilles de, x, 37 Corcovado Peak, xiv, 112 Cordage, sources, xiii, 238-41 Cordaitales, xiii, 310, 317 Cordaites, iii, 255, 256 Cordova, university of, xvi, 100 Cores, in electric machines, vii, 365 Cork, specific gravity of, iv, 109, 112 Cormorants, xii, 253; fish-catching with, xv, 223-4 Corn, American origin, xiii, 182, 211, 212, 221, 222; economic importance, 208; food value, viii, 364, 365, x, 262, 278, 279; grains of, fruits, xiii, 56; in grass family, 179; leaves of, 32, 176; monocotyledon, 178; stalks, glucose from, ix, 230; stalk structure, xiii, 26; starch manufacture from, viii, 243; time to plant, i, 255; tryptophane in, viii, 351; weather best for, i, 245-8 (see also Indian Corn) Corn Crakes, xii, 262 Cornea, of eye, ix, 109, 110 (fig.), xi, 84, 85; astigmatism of, ix, 113-14; no warm spots in, xi, 112 Cornets, iv, 231 Corn Flour, vitamines in, x, 267 Corn-Harvesting Machines, v, 249 Corn Syrup, as food, ix, 292; vitamines in, x, 262 Corolla, xiii, 45; absent in some plants, 46, 182; evolution of, 201