Architecture, notes on, xxiv, 257.^f ----, in the United States, xvii, 99, 249^f; xviii, 11, 212. ----, Grecian style, the propriety of its application to modern uses, xviii, 218. ----, Gothic style, notice of, xviii, 220. Architectural improvements, _E. Lord_, xxv, 304. ---- monuments, xviii, 229. Arctic regions, sketch of geology of, xvii, 1. Argentine, notice of, _C. Dewey_, vii, 248. ----, analysis of, _C. Dewey_, vi, 333. ----, locality of, in Massachusetts, viii, 34. Argento-cyanate of silver, for fulminating silver, xviii, 335. Argento-cyanic acid, xviii, 334. Argillaceous slate, in western Massachusetts, viii, 18, 21, 29. Argillite, of the Connecticut valley, account of, vi, 35. Aristotle, notice of, _C. Fox_, xxxvi, 217. Armature, see _Electro-magnet_, and _Magnet_. Arragonite, analysis of, _M. Stromeyer_, vii, 368. ----, in Canada, viii, 70. ----, in New York, xxi, 326; xxviii, 172.^f ----, of New Jersey, _J. Finch_, xviii, 197. Arragonite and calc spar, _Becquerel_, xxiii, 387. Arsenic, on the detection of, _L. Feuchtwanger_, xix, 339.^f ----, application of Riench's test, _D. P. Gardner_, xliv, 240. ----, on the detection of, _J. L. Smith_, xl, 278; xlii, 75.^f ----, tests for, iii, 354; iv, 155; xliv, 213. ----, on the iodide of potassium a test for, _J. P. Emmet_, xviii, 58. ----, tobacco a remedy for, xxxi, 188. ----, oxide of iron an antidote for, xxviii, 135. ----, effect of, on vegetation, _Daubeny_, xxxi, 346. Arsenical iron, in N. York, xxi, 326. ---- ----, (Danaite) in N. Hampshire, analysis of, _A. A. Hayes_, xxiv, 386. ---- ---- ----, identical with mispickel, xlvi, 384.^f Arsenious acid and sulphuric, a new compound of, xli, 47. Artesian wells, see _Wells_. Artificial minerals, _A. Crosse_, xxxi, 374. ---- diamond, pretended, xvi, 394. ---- feldspar, xxviii, 396. ---- sulphate of lime with half an atom of water, _J. F. W. Johnston_, xxxv, 300. ---- minerals, produced by heat, x, 190. ---- oxyd of iron, about furnaces, xxxvi, 237. ---- mineral waters, _S. Morey_, iii, 94. Asbestus, in Connecticut, i, 354. ----, in Maryland, xviii, 80. ----, in Massachusetts, i, 114; viii, 47. ----, in New Hampshire, vi, 245. ----, in N. York, i, 237; ix, 40, 252. ----, in Pennsylvania, x, 221. ----, in Vermont, v, 40; vi, 249. ----, in anthracite, i, 243, 244. ----, covering for firemen, xviii, 177; xx, 96.^f Asclepias, on the fibre of, xxviii, 380. Ashes, shower of, at Vesuvius, iii, 374. ----, volcanic, at sea, west of the Philippines, _P. Parker_, xl, 198. ----, of two pines, composition of, xxvi, 182. ----, spontaneous combustion in, _O. P. Hubbard_, xlii, 166. ----, combustibility of, _J. T. Plummer_, xlii, 167; xliii, 80. ----, various properties of, _J. T. Plummer_, xliii, 85.