_Plummer, J. T._, miscellaneous observations on insects, xl, 146. ----, motion of particles of melted spermaceti of a burning candle, xl, 148. ----, suburban geology, (Indiana) xliv, 281.^f ----, fucoids in Indiana, xliv, 290.^f ----, scraps in natural history, xlvi, 236; xlviii, 93. ----, horticultural experiments, xl, 197. ----, on the dry-rot, xlii, 197. ----, combustibility of wood ashes, xlii, 167.^f ----, on a dangerous property of wood ashes, xliii, 80. Plumose mica, ii, 141. Pluranium, announced as a new metal, from the Ural, xvi, 384. Pluviometrical observations, see under _Rain_ and _Meteorological_. Pneumatic cistern of _R. Hare_, xiv, 200^f; xxxiii, 246.^f ---- paradox, on the true theory of, _J. H. Abbot_, xxxix, 296^f; xl, 144.^f Poa modesta, xlv, 45. Poacites, fossil plants, generic characters of, vii, 182. Poem, geological, v, 272. Poison of the Argas persicus, xxxiii, 271. ----, Senecio obovatus poison to sheep, xv, 358. ---- of the common toad, xiv, 373. Poisons, animal, ii, 168. ----, ----, antidotes for, ii, 358. ----, ----, salt a remedy for, xxi, 158. ---- ----, ammonia an antidote against, xvi, 182. ----, ----, the Uvularia perfoliata a remedy for, _B. H. Coates_, xxxv, 270. ----, action of, on vegetables, xii, 196; xv, 169. Poisonous confectionary, xviii, 157. _Poisson, S. D._, on the temperature of the earth, atmosphere and of space, xxxiv, 57. ----, death of, xl, 220. Poland, a history of, published by N. Rosenfield, vi, 390. Polanisia, i, 378. Polar, north, fogs of, xiv, 378. ----, ----, account of explorations, i, 101; xvi, 124. Polariscope, for polarized light, xv, 369.^f ----, natural, of tourmaline in mica, _B. Silliman, Jr._, xlvii, 418. Polarity, new kind of, in light, _D. Brewster_, xxxv, 292. ---- of molecules in crystallization, _J. D. Dana_, xxx, 275.^f ----, electric, see under _Electricity_. Polarization of heat, xxviii, 366, 397. ---- ----, remarks on, _J. D. Forbes_, xl, 317. ---- of light by reflection, _D. Brewster_, xxii, 277.^f ---- by refraction, laws of, _D. Brewster_, xxiii, 28^f, 227.^f ----, use of mica in, _J. D. Forbes_, xxxviii, 101. ----, elliptical, of reflected light, _B. Powell_, xliv, 171; xlvi, 390. ----, auroral light without, _J. Henry_, xxxix, 366. Polarized rings produced in specimens of decomposed glass, _D. Brewster_, xl, 325. ---- light, exhibited by means of oxy-hydrogen microscope, xxxviii, 102. Polarizing rocks, xx, 198. Pole, north, attempts to discover, i, 101. Polishing of granite, iv, 246; viii, 185. Pollen, analysis of, _M. Prinsep_, xviii, 402. ----, yellow showers of, xxxix, 399; xlii, 195. ----, ---- ----, examined by _J. W. Bailey_, xlii, 196.^f Polycrase, a new mineral species, xlix, 394. Polygons, on the measure of, _G. C. Whitlock_, xlvii, 380.^f Polyhydrite, xlii, 386. Polynesian Islands, new work on, xxix, 290.