_Griffith, Mary_, on the halo which surrounds all bodies, xxxviii, 22. Grindstones of Nova Scotia, xv, 148; xxx, 338. _Griscom, J._, on botanical fêtes in France, ix, 154. _Griswold, C._, submarine explosion, ii, 94. _Gronovius, J. F._, letters from, to C. Colden, xliv, 85. Grooves in rocks, see _Scratches_. Grotto del Cane, xxiv, 244. Grove's voltaic battery, xxxviii, 116. ---- ---- ----, experiments with, _S. F. B. Morse_, xlv, 390.^f ---- ---- ----, on the use of carbon in, _B. Silliman, Jr._, xliii, 393; xliv, 180.^f Groves of evergreens, their value near gardens, &c., xxii, 158. Growth of wheat, on the acceleration of, _G. W. Hall_, xxxi, 345. ---- of timber, xxiv, 391. Guaco, notice of, xxii, 182. ----, medical virtues of, confirmed, _W. R. Johnson_, xxvii, 171. ----, remedy for hydrophobia, _W. R. Johnson_, xxiv, 279. ----, note on, xxiv, 388. Guadaloupe fossil human skeleton, description of the skull of, _J. Moultrie_, xxxii, 361. Guano, remarks on, _J. E. Teschemacher_, xlvi, 203. ----, account and analysis of, xlviii, 181. ----, change in bones in, _R. Warrington_, xlix, 391. ----, xanthic oxide in, xlix, 200. ----, xanthine in, _Unger_, xlix, 391. _Guillemin, J. B. A._, on the bitterness of vegetables, xxiv, 273. Gulf of Mexico, accumulation of water in, supposed from the action of the Gulf Stream, v, 353. Gulf Stream, cause of, v, 353. ---- ----, existence of, determined by _B. Franklin_, xlvii, 162. ---- ----, supposed connection of, with opposite currents on the coast of the United States, _W. C. Redfield_, xxxii, 349. ---- ----, extent of, xxxii, 350. ---- ----, ice of the north brought within the dissolving influence of, on the Newfoundland bank, _W. C. Redfield_, xxxii, 351. ---- ----, loss of vessels in, xx, 158. ---- ----, remarks on, _M. F. Maury_, xlvii, 161. Gum, composition of, xxii, 350. ---- ammoniacum, xx, 399. Gun barrels, browning of, xxxiv, 45. Gunpowder, _A. Ure_ on the composition of, xx, 190. ----, experiments on, _A. Mordecai_, xlix, 180. ----, inflamed underwater, xxii, 354. ----, method of augmenting the force of, _Geo. Gibbs_, i, 87. ----, safe process for manufacturing, _S. Guthrie_, xxi, 292. _Guthrie, S._, mode of obtaining chloric ether, xxi, 64; xxii, 105. ----, chemical products by, xxi, 92. ----, fulminating preparations, xxi, 288, 293. ----, gunpowder, safe process, xxi, 292. ----, molasses from the potato, xxi, 93. ----, sugar from potato starch, xxi, 284. ----, purification of turpentine, xxi, 291. ----, pure oil of turpentine, xxi, 93. ----, vaporization of mercury in the fumes of nitric ether, xxi, 90. Gymnasium at New Haven, xiii, 385; xiv, 400. Gymnastic science in France, x, 176. Gymnastics in Switzerland, v, 191. Gypsies, essay on, xxiv, 342. ---- in America, xxvi, 189.