Spectacle glasses, manufactory of, xxvii, 80.

Specula for telescopes, improvement in, xliv, 166.

The American Journal of Science and Arts, Volume 50 (First Series) — Part 219

Speculum, _Nasmyth's_ pneumatic, xxxviii, 107.

The American Journal of Science and Arts, Volume 50 (First Series) — Part 219

_Spencer, A._, vindication of claims, relating to the graphic art, xliv, Appendix.

The American Journal of Science and Arts, Volume 50 (First Series) — Part 219

_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.

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.

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.

Spontaneous combustion, instance of, iii, 383; v, 201; xxii, 161; xxvii, 178; xxxiii, 147. ---- ---- in wood ashes, _O. P. Hubbard_, xlii, 165. ---- ----, remarks on, _J. Mease_, xxxiii, 147, 199. ---- ---- of coal, xxxiii, 147. ---- ---- of linen, cotton, &c. with linseed oil, xxxiii, 148. ---- ---- of oatmeal, xxxiii, 150. ---- ---- of lampblack, xxxiii, 150. ---- ---- of horse-manure, xxxiii, 151. ---- ---- of coal, xxxiii, 200. ---- ---- of wood, xxxv, 144. ---- generation, remarks on the theory of, _C. A. Lee_, xxxix, 289.