---- ----, at Westchester, Pa., observations by _A. D. Bache_, xxvii, 385. Magnetism, animal, v, 192; xiii, 175. ----, _Davis's_ Manual of, xliii, 381. ---- of the earth, especially of the arctic regions, _E. Sabine_, xvii, 145.^f ---- ----, causes of, _B. F. Joslin_, xix, 398. ---- ----, views of _J. Hamilton_, xxxvii, 100. ---- ----, views of _S. L. Metcalf_, xxvii, 153. ---- ----, views of _Rowall_, xli, 41. ---- ----, effect of, on the precipitation of silver, xvi, 262. ---- chemical effects of, viii, 374. ----, supposed influence of, in combinations and crystallizations, by _O. L. Erdmann_, xviii, 395. ----, influence of, xvi, 262. ----, connexion of, with electricity, iii, 386.^f ----, connexion of, with heat and electricity, _J. F. Dana_, vi, 163. ----, ----, with light, _G. Gibbs_, i, 89. ----, ----, with geology, _J. Locke_, xlvii, 101. ----, conversion of, into electricity, xxii, 386. ----, currents and sparks of electricity from, _J. Henry_, xxii, 403. ----, destroyed by lightning, xii, 382. ----, Gauss's theory of, tested by observations, _E. Loomis_, xlvii, 278. ----, _Hansteen's_ discovery in, v, 190. ----, influence of heat on, xxii, 361. ---- of soft iron, acquired by induction, retained for some time if the armature is not removed, xxviii, 63. ----, molecular forces, on the disturbance of, by, _C. G. Page_, xxxiii, 118. ---- produced by friction, xix, 394. ---- ---- by a stroke of lightning, vi, 394. ---- ---- by voltaic electricity, iii, 383. ---- ---- by the solar rays, xiii, 171. ----, double helix for inducing, _C. G. Page_, xxxv, 261.^f Magnetization, some phenomena of, _De Nairac_, xxvii, 401.^f Magneto-electric apparatus, and experiments, _J. P. Emmet_, xxiv, 78^f; xxvi, 311; xxviii, 331. ---- - ---- ---- ----, _J. Henry_, xxviii, 331. ---- - ---- ---- ----, _E. M. Clarke_, xxxiii, 213.^f ---- - ---- ---- ----, _C. G. Page_, xxxiv, 163^f, 364^f; xxxv, 112^f, 252^f; xxxvii, 275^f; xlviii, 392. ---- - ---- ----, _O. W. Gibbs_, xxxix, 132. ---- - ---- ---- ----, _J. H. Abbot_, xl, 104.^f ---- - ---- electrepeter, _E. M. Clarke_, xxxiii, 224.^f ---- - ---- ----, _C. G. Page_, xxxv, 112.^f ---- - ---- electrotome, _C. G. Page_, xxxv, 112^f, 253.^f ---- - ----, formula, xxxv, 356.^f ---- - ---- multiplier, _C. G. Page_, xxxvii, 275.^f ---- - ---- shock increased by a long coil, _J. Henry_, xxviii, 331. ---- - ---- ---- increased by passing it through a portion of the generating magnet, _J. P. Emmet_, xxviii, 331. Magneto-electricity, _J. Locke_, xxxiv, 125.^f Magnetometer, new, _A. D. Bache_, xl, 380. Magnolia grandiflora, xxvi, 314. Mahogany, artificial, ix, 206. Mahomet Ali, notice of, xxviii, 30.