Tyler, J. W., solar halo, seen at Cazenovia, N. Y., xxi, 189.
Tyrannula, see under [Zoology.]
Tyrian dye, xxxviii, 126.
Tyson, P. T., on the minerals of Baltimore and Harford Cos., Maryland, xviii, 78.
U.
Ulcers cured by chloride of lime, xiii, 179.
Ultramarine, artificial, xv, 392; xxii, 368; xxiv, 373; xxvii, 195; xxviii, 144.
Unger, on xanthic oxide in guano, xlix, 200, 391.
Unicorn, on the existence of, J. F. Laterrade, xxi, 123.
Unio, see under [Zoology, Mollusca.]