_Nicollet, J. N._, on the cretaceous formation of the Upper Missouri, xli, 180; xlv, 153. ----, drift not accounted for by the glacial theory, xlv, 323. ----, on the mineral region of Missouri, xlv, 340. ----, obituary of, xlv, 404; xlvii, 139. _Niepce_, photographic processes of, xxxvii, 173, 374. Niger, mouth of, iv, 373. Nile, the mouth of, xxviii, 24^f, 28. Nineveh, ruins of, _A. Smith_, xlix, 113. Niobium, new metal, xlviii, 400. Nitrate of lime and of potash, i, 65. ----, of silver, preparation of, v, 348. ----, ----, preparation of pure, xxiv, 370. ----, ----, pure not blackened by sun's rays, xxxv, 298. ----, ----, reduction of, xviii, 400. ----, of soda of Atacama, Peru, xii, 385. ----, ----, of Tarapaca, _A. A. Hayes_, xxxviii, 410; xxxix, 375. ----, ----, of Tarapaca, mode of refining, xliv, 7. Nitre, origin of, xxviii, 292. ----, native, i, 146. ----, ----, in caves of Kentucky and elsewhere, viii, 323. ----, ----, in Africa, i, 147. Nitric acid, on fuming, _Mitscherlich_, xx, 185. ---- ----, remarks on its solvent power on metals, _Millon_, xlvii, 191. ---- ----, _J. Liebig's_ new test for, xvii, 176. ---- ----, ibid, _J. W. Bailey_, xxxii, 85. ---- ----, effect on sulphuretted hydrogen, viii, 375. ---- ----, action of, on certain metals, xxxiii, 286. ---- ----, action of, on iodine, xxi, 376. ---- ----, fumes, use of, in pulmonary diseases, xxxvi, 191. ---- ----, eyes of insects reddened by, xxx, 196. ---- ----, and phosphorus, explosion from, xvi, 366. ---- ether, process for, _R. Hare_, xxxiii, 241.^f Nitrification, theory of, xiv, 385. Nitrogen, abstracted from the atmosphere by organization, geological proofs of, _L. Vanuxem_, xii, 84. ----, different modes of obtaining, xxviii, 360. ----, apparatus for procuring, _R. Hare_, xiv, 356^f; xxviii, 263.^f ----, mode of preparing, xlix, 195. ----, specific gravity of, xxxv, 298. ----, on the office of, in respiration, _L. C. Beck_, xviii, 52. ----, reduction of metals by, xix, 371. ---- in animal substances, researches relative to, _Macaire_ and _Marcet_, xxiii, 384. ---- ---- ibid, on the determination of, xxviii, 134. ---- ---- ibid, _Bunsen's_ method of estimating, xli, 53. ---- ---- ibid, new method of determining, _Varrentrapp_ and _Will_, xlii, 253^f; xlv, 267. ----, combines with iron and copper, xxiv, 374. ----, phosphuret of, xxviii, 140. ----, combined with boron and silicon, forming combinations analogous to cyanogen, xlvii, 192. ----, chloride of, properties of, _G. S. Serullas_, xviii, 155. ----, new compounds of, (Mellon, Melam, &c.) _J. Liebig_, xxix, 371. ----, gas at Hoosic, N. Y., xv, 234. ----, formation of, in warm springs, _C. Daubeny_, xx, 383. ----, springs in New York, analysis of, xxxvi, 7. ---- ----, see _Springs_. Nitroline, analysis of, xlix, 204.