434. 
INDEX. 
Pendulurrij on the length of, 325. 
Phosphorescence of the Mediterranean, 237.— of minerals, account of 
the, 383. 
Playfair j Professor, on the slide of Alpnach, I93. — witnesses the ex- 
periments of Morichini on the magnetising influence of the violet 
rays, 241. 
Poissons researches on wind instruments, 204. — on the libration of 
the moon, 198. 
Polarisation of light, history of, 289- ' 
Potash found in sea- water, 417. 
Prime numbers, demonstration of a theorem relating to, 46. 
Prizes adjudged, 218. 
Pump, description of an improved self-acting, 79* 
Purpuric acid, 209. 
Pyramid, great, recent discoveries respecting, 88. 
Pyro-electricity of Tourmaline, 205. — of Nadelstein, ib. 
Q 
Qjuartz-roch, geognostical relations of, 113. 419* 
R 
Rafnesque on meteoric dust, 425. 
Rainbow, Dr Watt’s theory of, 203. 
Red Sandstone, geognostical relations of, 115. 
Refraction, case of unusual, 411. 
double, history of, 289. 
Repeating circle, 199* 
Ridolfi’s experiments on the magnetising influence of the violet 
rays, 240. 
Robertson, Dr, on the tides of the Mediterranean, 236. — on the lumi- 
nous appearance of its waters, 237. 
Ross, Captain, account of his expedition to Baffin’s Bay, 150. 
Royal Society of Edinburgh, proceedings of, Ipl. and 404. 
Rumker, Mr, on the longitude and latitude of Valetta, 280. — on the 
position of thirty-four places in the Mediterranean, 322. — ^his cal- 
culation of the orbit of the comet of I8I9, 402. 
Russel, Professor, on a singular affection of vision, 271. 
S 
Salt mines of Villiczka, 41 9. 
Sap, motion of, in vegetables, 219- 
Scoresby, Mr, on the size of the Greenland whale or Balsena mysticetus, 
83. — his narrative of an excursion upon the island of Jan Mayen, 
containing some account of its appearance and productions, 121. 
— on the effects of the sea at great depths in augmenting the spe- 
cific gravity of woods, 363. — his method of travelling to the Arctic 
regions, 408. 
Sea water from the Arctic regions, quantity of saline matter in, I60. 
Shetland, account of the rocks of, 296. 
Sivright, Mr, on a new method of making single microscopes of 
glass, 81. 
