Physical Geography, effects of, on the boundaries of empires, _J. Finch_, xiv, 18. Physiology, some of the principles of, _A. Fourcault_, xix, 391. ----, animal, xxiv, 382. ----, vegetable, xix, 393; xxiii, 138; xxxiii, 290. _Pickering, C._, description of the Caligus americanus, xxxiv, 225.^f _Pickering, J._, notice of life of _N. Bowditch_, xxxv, 386. Pickeringite, analysis of, _A. A. Hayes_, xlvi, 360. Picropharmacolite of Rügelsdorf, vii, 368. _Pictet, M. A._, death of, x, 179. Pictured rocks of Lake Superior, composition of, v, 220. Pictures, transparent, ii, 348. _Pierce, E._, on meteoric iron from Otsego Co., N. Y., xlvi, 402. _Pierce, J._, native carbonate of magnesia on Staten Island, i, 142. ----, geology, mineralogy, scenery, &c. of the secondary region of a part of New York, New Jersey, and the adjacent regions, ii, 181. ----, on mineral waters, &c., iii, 235, 236. ----, on the geology, mineralogy, &c. of the Highlands of New York and New Jersey, v, 26. ----, geology, scenery, &c. of the Catskill Mountains, vi, 86. ----, notice of the alluvial district of New Jersey, with remarks on the marl, vi, 237. ----, an excursion among the White Mountains and up Mount Washington, viii, 172. ----, agriculture, geology, &c. of the Floridas, ix, 119. ----, topography, resources, &c. of Michigan, x, 304. ----, Virginia, shell marl and coal regions of, xi, 54. ----, mineral resources of Pennsylvania, xii, 54. _Pierce, L._, notice of a halo, x, 369.^f _Pierpont, J._, meteorological notes in 1692, xlii, 399. Pig, anecdote of, xlvi, 243. Pigeons, flight of, in Ohio, _S. P. Hildreth_, xxiv, 134, 136; xl, 348. ----, roosts of, in Ohio, xl, 348. ----, mode of decoying, xvi, 373. Pigment for the pallet, xvi, 174. Pilatus, Mount, slide of, iii, 368. Pimelite in Vermont, viii, 234. Pine timber, strength of, xix, 228.^f Pinguite, new mineral species, xx, 197. Pinite in Massachusetts, ix, 48. ---- (chlorophyllite) in Connecticut, vi, 219; xli, 354. ---- not at Bellows Falls, Vt., xi, 384. Pink dye, from the flower of the sweet balm, xxv, 413. Pipa, xi, 271. Piperine, use of, _G. W. Carpenter_, xiii, 326. ----, notice of, _T. G. Clemson_, xviii, 352. Piper leptostachyum, v, 287. Pipes, iron conduit, vi, 173. Pipestone, red, of the Côteau des Prairies, xxxvii, 393; xxxviii, 138. _Pirira_, on salicine, xlix, 392. Pisa, notice of, iv, 383. Pisolite in Massachusetts, ii, 238. Pisolitic balls, xliv, 283.^f Piston, Cooper's rotative, xvi, 313.^f Pittsburg, Pennsylvania, account of, _S. P. Hildreth_, xxix, 68, 79. _Pixii_, rotating magnetic machine, xxiv, 144, 146^f, 196. Plague in Constantinople, remarks on, xxxiv, 32. Planes, inclined, in the construction of rail roads, _J. Thomson_, xxiii, 107. Planera, or Siberian elm, notice of, xx, 377.