Alfalfa, fertilization, xiii, 138-9; in pea family, 198; nitrogen fixation by, xiv, 66 Alfonsine Tables, ii, 39, 44 Alfred the Great, language of, xv, 156; navy of, xiv, 261 Algæ, xiii, 72-3; classification work, xvi, 166; curious "showers" of, i, 358-9; fossils of, xiii, 303, 304 (illus.); found in hot springs, ii, 249, xiii, 299; in sea, xii, 16-7, xvi, 147; number of species, xiii, 323; oldest of plants, 303-4; reign of, 314, 323 Algeria, animals of, xii, 326, 359; dust storms, i, 54; record temperature, 209; snowfalls, 210 Algol, actual magnitude, ii, 321-2; secondary minimum, 328; type of variables, 325-6 Algonquin Lake, iii, 149-50 Alimentary Canal, ix, 233 (fig.); foci of infection in, x, 220; in infants, ix, 346; operation of muscles, xi, 37-8, 69; protection against germs, x, 202; sterile at birth, 201; X-ray examinations of, 373 Alimentary Disorders, x, 319-38 Aliphatic, defined, viii, 373 Alkali Industries, viii, 276-8 Alkali Metals, viii, 132-47 Alkalis, defined, viii, 373; deposits, 139; volumetric analysis, 292 Alkaloids, viii, 240 Allbutt, Clifford, xvi, 184; Osler and, x, 151; quoted, 35 Allegheny Plateau, xiv, 221; coal of, iii, 346-7; origin of present relief, 231-2 Allelomorphs, xvi, 157 Allergy, x, 216-7 Alligators, xii, 182, 196-8; savage methods of luring, xv, 222 Allotropic Forms, viii, 43, 87, 373 Alloys, viii, 272-3; aluminum, iii, 369-70; antimony in, viii, 169; copper, 164; electrolytic refinement, vii, 319-21; melting point of, iv, 161-2 Alluvial Cones, iii, 33 Alluvial Soils, xiv, 63, 70-1 Almanacs, ancient Greek & Roman, i, 67-8; Arabic word, ii, 39; weather predictions in, 243-4 (see also Nautical Almanacs) Alpenglow, i, 168, 366 Alphabet, invention & development of, xv, 175-6, xvi, 60 Alpha Centauri, magnitude, motion and type, ii, 319; parallax and distance, 312, 313, 314-15 Alpha Lyræ, drift of sun toward, ii, 18, 306; parallax, 312 Alpha Rays, i, 143, viii, 185 Alpine Glaciers, iii, 60, 62-3 Alpine Racial Group, xvi, 49-50