_Northrop, B. F._, fluid in hornstone, vii, 283. _Norton, W. A._, Treatise on Astronomy by, noticed, xxxvi, 197. ----, on the tails of comets, xlvi, 104.^f _Norton, J. P._, analysis of Sillimanite, xlvi, 382. Notices of books, see _Works_. Nova Scotia, short notice of the minerals of, xii, 176. ----, mineralogy of, _F. Alger_, xii, 227. ----, geology and mineralogy of, _C. T. Jackson_ and _F. Alger_, xiv, 305, with a map; xv, 132^f, 201; xxii, 167. ----, fossils in the iron ore of, xv, 201. ----, scientific excursions to, from Williams College, with an account of the minerals and geology of, xxx, 330.^f ----, fossils and fossil wood of, xxx, 339.^f ----, grindstones, xv, 148; xxx, 338. ----, coal, bituminous, xv, 149. ----, fossil trees, upright in the coal strata of, xlv, 353. ----, gas, from the coal mine of, xxx, 184. ----, coal and gypsiferous formation of, xlv, 356. Novaculite, or whetstone of North Carolina, v, 262; xiv, 238. ---- in Georgia, xvi, 185. ---- in Ohio, xvi, 374. ---- of Lake Memphremagog, Canada, v, 41, 406. Nucula, see under ZOOLOGY, _Mollusca_. _Nugent_, geology of some West India Islands, i, 140. _Nulty, E._, on formulæ for comets, xxxviii, 160. Number _five_, the most favorite of nature, xvi, 172. Numbers, interesting properties of, _G. R. Perkins_, xl, 112. ----, analysis of square, _A. D. Wheeler_, xxv, 87. Numerical faculties, theory of, vii, 285. Nutation, new determination of, _Peters_, xlvii, 90. Nutmeg, in Singapore, xliv, 153. Nutriment of gelatine, xxii, 197. Nutritious matter from an acre of land cultivated with potatoes or wheat, _Eli Ives_, i, 297. _Nutt, R._, on the origin and extension of prairies, xxiii, 40. ----, observations on the lower part of the Mississippi valley, xxiii, 49. _Nuttall, T._, plants collected in East Florida, v, 286. ----, serpentine rocks of Hoboken, iv, 16. ----, observations and geological remarks on the minerals of Patterson and the valley of Sparta, N. J., v, 239. ----, reply to _H. Seybert_, vi, 171. ----, Botany of, noticed, xiii, 99. ----, proposed work on birds, xx, 154. ----, ---- ----, noticed, xxii, 178. ----, North American Sylva, noticed, xliv, 194. O. Obesity, xxii, 194.