Aluminum, Aluminium, affinity strength, viii, 128; atomic weight and symbol, 383; chemical activity, 149, 155; compounds, unstable, 137, 257; density of, iv, 113; electrical conductivity, 283; electrolytic reduction, vii, 320, viii, 271, 284; gold plating of, vii, 319; in heavy metal group, viii, 126-7; melting point and heat, iv, 162, viii, 384; occurrence, 19, 129, 148, 154, 198; percentage in earth's crust, iii, 308, viii, 192; production and uses, iii, 369-70, viii, 154-5; salts astringent, 116; sound velocity in, iv, 201; specific gravity, viii, 384; test for, 287, 288-9 Aluminum Arresters, vii, 17, 50 Aluminum Wire, vi, 80, vii, 23 Amalgam, defined, viii, 373 Amalgamation, defined, vi, 132; in electric cells, 132, 139; in gold and silver extraction, viii, 131, 270 Amaryllis Family, xiii, 188 Amatus Lusitanus, x, 58 Amazon River, arapaima fish of, xii, 154; arrau turtle of, 193-4; Black caiman of, 198; electric eel of, 160; forests and swamps, xiii, 360; jaguars of, xii, 362; length and volume, xiv, 189; poison of natives on, xv, 228; tributaries, connections, xiv, 187; water boas of, xii, 216; water lily of, xiii, 359-60 Amazon Stone, iii, 328 Amber, in varnishes, viii, 265; insect remains found in, iii, 16, 280; magnetism of, iv, 256, vi, 11, 12 Ambergris, xii, 299 Ambrose Channel, dredging of, v, 257-8; sediment in, xiv, 269; wireless pilot system, vii, 284-5 America, antiquity of man in, xiv, 149; compass needle directions in, iv, 246; discovery and settlement of, xiv, 309-11; discovery of, effect on botany, x, 45; first hospital in, 81; plants restricted to, xiii, 320; vegetables and fruits originating in, 222-7 (see North and South America) American Buildings, dryness and heat in, i, 322-3, xiv, 353 American Colonies, Appalachian barrier, xiv, 191, 194, 242, 243, 249; first hospital, x, 81; independence results, 107; medicine in, 81, 104; ordeals practiced in, xv, 373; westward growth by rivers, xiv, 193-4 American Indians (see Indians) American System (Manufactures), v, 48-56, 213-14 Amethyst, iii, 337; oriental, 327 Amides, viii, 373; acid, 230 Amines, viii, 210, 214, 215, 373 Amino, defined, viii, 374 Amino Acids, chemistry of, viii, 230, 309-10; physiological origin and use, ix, 279-84, 287-8, x, 204, 277, 278, 279; proteins compose of, viii, 230, 351, 352 Amino Compounds, viii, 236-7 Amino Derivatives, viii, 210, 214, 215 Ammeters, iv, 279-80, vii, 165-72, 361; automobile, 121; galvanometers as, 179; hot-wire, 163-4