_Olmsted, D._, red sandstone of North Carolina, ii, 175. ----, geological survey of North Carolina, in contemplation, v, 202. ----, rocks and minerals of North Carolina, v, 257. ----, on the gold mines of North Carolina, ix, 5. ----, Report on the Geology of North Carolina, noticed, xiv, 230. ----, report on the state of chemical science in 1826, xi, 349; xii, 1.^f ----, on the materiality of heat, xi, 356; xii, 359. ----, notice of illuminating gas, from cotton seed, viii, 294; x, 363. ----, on the excessive use of sulphur, viii, 394. ----, meteorological report, for 1827, xiv, 176. ----, ---- ----, for 1828, xvi, 70. ----, on the phenomena and causes of hail storms, xviii, 1.^f ----, on adjusting lightning rods, xviii, 362. ----, reply to A. T. Christie on hail-storms, xx, 373. ----, on the New Haven tornado, July, 1839, xxxvii, 340.^f ----, on the nature and cause of the meteors of Nov. 13, 1833, xxv, 363; xxvi, 132.^f ----, cause of the meteors of November, xxix, 376; xxx, 370.^f ----, meteors of November, 1836, xxxi, 286. ----, ---- ----, 1837, xxxiii, 379.^f ----, ---- ----, 1838, xxxv, 368. ----, ---- ----, 1839, xl, 202. ----, ---- of different periods, xxvi, 132. ----, on the Aurora Borealis, xxix, 388; xxxii, 176. ----, on the Zodiacal light, xxvii, 416; xxix, 379. ----, on the eclipse of the sun, of Sept. 1838, xxxv, 174. ----, report of observations on the transit of Mercury, May, 1845, xlix, 142. ----, new experiments on the solar spectrum, xlviii, 137. ----, a paralytic affection cured by a stroke of lightning, iii, 100. ----, memoir of Eli Whitney, xxi, 201.^f ----, Natural Philosophy of, noticed, xxiii, 351; xxv, 214; xxxiv, 219. ----, Introduction to Astronomy by, noticed, xxxvi, 203. ----, Life and Writings of E. P. Mason, by, noticed, xl, 407; xliii, 381. Ontario valley, geological features of, xi, 213.^f ---- lake, level of, xxxiii, 122; xlv, 16. ---- ----, temperature of, xxxiii, 403; xxxvii, 242. ---- ----, ridge of, xxxvi, 40. ---- ----, evidences of changes of level about, xxxv, 104; xxxvi, 41; xlvi, 315. ---- ----, small lakes running into, xxxvi, 42. ---- ----, shore of, and height of water in, xxxvi, 43. Onyx, in Missouri, iii, 71. Oolitic formation in America, xl, 41. ---- ---- in New York, Orange Co., xix, 398. ---- ---- ----, in Saratoga Co., _J. H. Steele_, ix, 16.^f ---- ---- in Ohio, xlii, 233. ---- fossils, remarks on, xxxiii, 107. Oology, notice of _W. Hewitson's_ work on, xxxvii, 166. Opal at Vienna, a large, xii, 384. ---- from the graphite mine of Pfaffenreith, one-third water, xv, 390. Opelousas, geological notice of xxxv, 344. Ophisaurus ventralis, i, 262. Opiamon, xlix, 205. Opianic acid, xlvii, 196; xlix, 205. Opiano-sulphurous acid, xlix, 205.