—, spontaneous, iii, 383; v, 201; xxii, 161; xxvii, 178.
—, —, of various substances described, J. Mease, xxxiii, 147.
— of ashes, xlii, 165.f
Comet of 1819, ii, 374.
— of 1822, notice of, ix, 199, 367.
— of 1823, 1824, observations on, viii, 315.
—, Olbers's elements of, xiii, 189.
—, Biela's, notice of, xxiii, 390.
—, —, elements of, 1832, xxiv, 346; xxv, 191; xxviii, 398.
—, —, supposed possibility of collision with Encke's, xxiv, 346.