ON THE CHANGE OF REFllANGIBILITY OF LIGHT. 409 Polarized light, direction of the vibrations in, 183. Quartz, transparency of, 202, 217—219; train, 204, H. Quinine, absorption of the violet by a solution of sulphate of, 11; internal dispersion in a solution of, 14—20; strong affinity of, for hydrochloric, hydrobromie and hydriodic acids, 205—211. liayn, conrHG of, exhibited, 193. Itelleeting power (see Absorbing power). Befrangibility of dispersed light, lower than that of the incident, 80, 102, 230—230; nature of the, 81, 82; illustrated by a surface, 84, 85. Besults, principal, 240. Screen, on the choice of a, 189—192, F, G. Sea-weeds, red, 121—126. Strata of equal dispersion in crystals, 167. Test objects, 110, 114, 200. Triangle, experiment with a paper, 58. Turmeric, tincture of, 42; paper, 87—91. Uranium, salts of the peroxide, &c., 157—162, 213, C, I (see also Canary glass); delicate test of, 159; absorption of light by salts of protoxide of, 160, 163. Washed papers, 87—98.