— —, with light from nitre, &c., peculiarities of, D. Brewster, xliv, 163.
— —, action of gaseous and other media on, xlii, 157.
— —, photographic impression of, and phenomena of, J. W. Draper, xliv, 204.
— —, new experiments on, D. Olmsted, xlviii, 137.
— rays, magnetic influence of, xiii, 188.
— —, electricity of, xvii, 391.
— —, see farther under [Light.]
— spots, first observations on, xxiv, 204.
— —, in 1825, connection of, with temperature, xii, 199.
— —, in Nov., 1837, D. Olmsted, xxxiii, 393.f