—, magnetism, production of currents of electricity and sparks from, xxii, 403.
—, magnetic attraction and repulsion, reciprocating motion of, xx, 340.f
—, — needle, disturbance during an Aurora, xxii, 143.
—, soap-bubble, experiments with, on molecular attraction, xlviii, 215.
—, spark from a long conductor in a galvanic battery, xxviii, 327.
—, spiral conductor, action of, xxviii, 329.
Henry, W., on the disinfecting powers of increased temperatures, xxi, 392; xxii, 111.f
—, philosophical character of Priestley, xxiv, 28.
Hentz, N. M., on North American spiders, xxi, 99.f
—, a new sub-genus of spiders, xli, 116.f