Specific gravity, considered as a mineralogical character, xvi, 260. ---- ----, on the means of taking, _R. Hare_, xi, 121.^f ---- ----, a new instrument for, _F. H. Baddely_, xviii, 263.^f ---- ---- of gases, a modification of the method for ascertaining, _R. Hare_, xvi, 293. ---- ---- ----, _T. Thomson's_ method of taking, ii, 362. ---- ---- of nitrogen, oxygen, chlorine, and of the vapors of carbon, sulphur, arsenic and phosphorus, xxxv, 298. ---- ---- of various minerals, _A. Breithaupt_, xxxi, 268. ---- ---- of seawater, v, 129. ---- heat of the gases, notice of _de la Rive's_ and _Marcet's_ memoir on, xiii, 394. ---- ---- of certain solids, method of determining, xxvii, 267. Spectacle glasses, manufactory of, xxvii, 80. Spectrum, solar, see _Solar_. Specula for telescopes, improvement in, xliv, 166. Speculum, _Nasmyth's_ pneumatic, xxxviii, 107. _Spencer, A._, vindication of claims, relating to the graphic art, xliv, Appendix. _Spencer, T._, on the electrotype and its use, xl, 157.^f Spermaceti, composition of, products of distillation of, and oxidation of, by nitric acid, _J. Lawrence Smith_, xliii, 301. ----, moving particles in, when burning, xl, 148. Sphene in Canada, viii, 76. ---- in Massachusetts, vii, 53, 254; xxiv, 397. ---- in New Jersey, v, 243, 244. ---- in New York, ix, 40, 41, 251, 402; xxi, 326. ---- in Pennsylvania, x, 220; xiv, 7, 18. ---- in Vermont, iv, 276. Sphenophyllites, generic characters of, vii, 182. Spherical trigonometry, elements of, xvii, 415. Sphinges, North American, xxxvi, 282. Spiders, mode of forming the web of, xviii, 165. ---- and spider-webs, _J. Edwards_, xxi, 109.^f ----, gossamer, xvi, 399. ----, snake suspended by, xxvii, 307.^f ----, see farther, ZOOLOGY, _Articulata_. Spinel in New York, viii, 92; ix, 242, 251; xxi, 326. ---- in New Jersey, v, 244; ix, 245. Spinning frame, Brewster's, x, 130. ---- machine, worked by mice, in Scotland, viii, 371. Spiral of Archimedes, _A. B. Quinby_, ix, 316.^f ---- conductor, on the action of, _J. Henry_, xxviii, 329. Spirits, evaporation of, iii, 376. Spitzbergen, some account of, xvi, 144. Spix and Martius, reception of, at Munich, iv, 383. Spodumene in Massachusetts, vi, 225 and vii, 30 (called white Augite); viii, 120, 243; ix, 20; xiv, 220; xx, 170. ---- from Sweden, vii, 371. Sponges on the shores of Long Island, _C. S. Rafinesque_, i, 149. Spongia patera, or Neptune's goblet, _A. A. Gould_, xxxvi, 386. Spongy platina, _Döbereiner's_ discovery and researches, vii, 387; xviii, 151. ---- ----, _J. Liebig_ on, xviii, 398. ---- ----, action of, prevented by certain gases, xxxi, 348. ---- ----, ----, _Kuhlmann_, xxxvii, 198.