—, 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.