France, botanical fêtes, ix, 154. ----, fires in, few, xxv, 291. ----, mortality of infants, xix, 192. ----, phthisis in, 1828, xix, 193. ----, population of, xv, 397. ----, scenery in some parts of, x, 167. Franconia iron works, viii, 180. Franklin, B., original letters of, iv, 357; v, 157. Franklinite, ii, 323; v, 41, (shot ore,) 242, 400. _Fraser, John_, botanical labors of, _A. Gray_, xlii, 9. Fresco painting, means of detaching, iv, 384. Fredonia gas works, xvii, 398. Freestone of Sugar Loaf mountain, Maryland, xxvii, 21. Freezing mixture, _Boutigny's_, xxx, 168. ---- ----, xii, 195. ---- point, influenced by pressure, _L. C. Beck_, xlv, 49. ---- water, effect from, in a Leyden jar, viii, 374. ---- ----, by the aid of sulphuric acid, apparatus for, _R. Hare_, xxvii, 132.^f _Frodsham, W. J._, on the vibration of pendulums with different suspending springs, xxxvii, 278. ----, elected a member of the Royal Society, xxxvi, 195. Frogs, introduction of, into Ireland, xxviii, 398. ----, in rocks, remarks on, _D. Thomas_, xix, 167. Fromont garden, account of, xx, 83. Frozen wells, xxxvi, 184. Fruit, method of preserving without sugar, xv, 381. ----, fossil, of Zamia, &c., _G. A. Mantell_, xlv, 401. ---- trees, to destroy worms attacking, xxvii, 197. ---- ----, propagation of, xxvi, 183. ---- ----, time of flowering and other memoranda for different seasons, at Marietta, Ohio, see _Floral Calendar_ and _Meteorological Register_. Fucoids and other marine plants, _Ad. Brongniart_, ix, 375. ---- in Indiana, _J. T. Plummer_, xliv, 290.^f ---- in rocks of western N. York, xxxvi, 46. ---- in Pennsylvania, xx, 415; xxvii, 347. Fucoides Harlani, xxxvi, 46; xlviii, 299.^f ---- bilobata, xlviii, 307.^f ---- demissa, xlvii, 360.^f Fuego, Tierra del, rush of, xviii, 189. Fuel, _E. North_ on, xi, 66. ----, amount of, consumed in New York city, xvi, 360. ----, economy of, _W. R. Johnson_, xxiii, 318.^f ----, of coal tar and water, _C. Daubeny_, xxviii, 71. Fulgurites, or lightning tubes in sand, xx, 396. ----, siliceous tubes, Rome, N. Y., _C. E. West_, xlv, 220. ----, near Dresden, remarkable, xlvi, 210. ----, in chalk, cause of, _C. Lyell_, xxxviii, 122. Fuller's earth in Connecticut, ii, 217. Fulminating compounds, preparation of, _S. Guthrie_, xxi, 288, 293. ---- gold, ii, 350; xlviii, 142. ---- silver, xviii, 335. ---- ----, of _Berthollet_, xviii, 155. ---- ----, _Mitscherlich's_ mode of preparing, xix, 379. ---- ----, injury to _R. Hare_ from the explosion of, xxii, 185. ---- powders, caution against, i, 168. ---- ----, use of crackers of, xxvi, 187. ---- ----, of cyanogen and calcium, _R. Hare_, xxxvii, 268. ---- ----, new, made with saltpetre, sulphur, &c., xvi, 397. Fulminic acid, composition of, x, 191. Fumigation, x, 379. ----, in Sweden, vii, 188.