Flour, potato, used in making bread, xvi, 391. ----, detection of, in wheat, xvii, 173. ---- from leguminous fruits, vii, 189. Flowers, double, produced by depriving flowers of their anthers, _E. T. Leitner_, xxiii, 45. _Floyd, J._, hurricane near Calcutta, of April, 1838, xxxvi, 71. Fluidity of the earth's centre, _L. Cordier_, xv, 109, 117. ----, ----, ----, _Fourier_, xxxii, 1. Fluids, compression of, xxi, 381. ----, revolving motion in, xix, 391. ----, resistance of, _L. R. Gibbes_, xxvii, 135. ----, ----, _A. Bourne_, xxviii, 231. ----, resistance of, _E. W. Blake_, xxix, 274; xxx, 359. ----, ----, _Russell_, xxix, 351. ----, ----, _G. W. Keely_, xxviii, 318^f; xxx, 164; xxxi, 111. ----, upward forces of, _E. C. Genet_, xi, 110, 339^f; xii, 94, 310; xiii, 377. ----, ---- ----, _T. P. Jones_, in reply to _E. C. Genet_, xiii, 79. Fluor-spar, of Canada, viii, 71. ----, of Connecticut, ii, 141; v, 254; vi, 212. ----, of Indiana, (Shawneetown,) i, 52; ii, 176; iii, 243, 367. ----, of Massachusetts, i, 136; iv, 50; v, 405, 407; vii, 54. ----, of New Hampshire, xviii, 133, 291; xxxiv, 117. ----, of New Jersey, v, 246. ----, of New York, iii, 235, 367; xxviii, 176. ----, of Pennsylvania, x, 221; xiv, 5. ----, of Rhode Island, viii, 231; ix, 46. ----, of Tennessee, iv, 51. ----, of Vermont, iv, 43, 188; v, 272; vii, 59. ----, of Virginia, iii, 243; iv, 277. ----, of Sicily, viii, 205. ----, chlorophane variety in Connecticut, ii, 141; v, 254; vi, 212. ----, new phenomenon of color in, xxxv, 295. Fluoric acid in mica, ii, 376. ---- ----, its application to etching glass, vi, 354.^f ---- ---- and fluates, xiv, 387. Fluoride of iodine, _H. B. Leeson_, xlix, 205. Fluorine in bones, notice of investigations regarding, xlvii, 419. ---- ----, _J. L. Smith_, xlvii, 131. ---- ----, source of, _J. L. Smith_, xlviii, 99. ---- in recent bones, _C. Daubeny_, xlviii, 186. Fluxions, a theory of, _E. Wright_, xiv, 330^f; xv, 196; xvi, 53.^f ----, solution of a problem in, _T. Strong_, xvi, 283; xvii, 69, 329; xviii, 67. (See _Forces_, next page.) Fluxional ratio, application of, _E. Wright_, xxiv, 298^f; xxv, 93.^f Flying in the air, _De Chabrier's_ views on, xix, 395. Fogs, remarks on, _W. C. Redfield_, xxxiii, 54. ----, on the formation of, _W. M. Carpenter_, xliv, 40. ----, polar, xiv, 378. Food for sheep, different kinds of, xxiii, 393. _Foot, L._, on Indian summers, xxx, 8. ----, notices in geology and mineralogy, iv, 35.