INDEX. 
407 
Phosphoric acid in vegetables, S82. 
Pinna Marina j s\]k oi, 
Polarisation of light, history of discoveries respecting it, I67. 
I — circular, 179* 
Pole, North, nearest approach to, 398. 
Poppy -oil, method of manufacturing, 15. 
Porphyry, columns at Rome, 355. 
Potash, ‘from potato-stalks, 399— in vegetables, 304.-~in sea-wa- 
ter, 325. 
Proportional Logarithms, table of, ^6. 
Proteus, account of the, 388. 
Purpuric-acid, 187. 
Pyrenees, geognosy of, 397* 
R 
Rain, Red at Blankenberg, 381. — ^black at Montreal, ib. 
Repeating circles, on the error of, 183. 
Ripples^ remarkable ones in the Straits of Malacca, 7* 
Robison, Mr, on a malleable-iron passage-boat, 222. 
Rose, Ayrshire, Mr Neill on the, 102. 
Royal Society of Edinburgh, proceedings of, 179i ^73. 
S 
Salt, annual quantity of, raised in Europe, IQO. 
Saussure, M. de, on the decomposition of Starch, 382. 
Sap in plants, Amicfs discoveries respecting it, 135. 
Sawings of wood, on sugar from, 363. 
Sea-cuater, specific gravity of, 257* 
Sea, Greenland, temperature of, 359. — colour of, 10. 
Scoresby, Mr, on the colour of the Greenland Sea, 10.— -on the ano- 
maly in the variation of the needle, 184. — on the fixed icebergs of 
Spitzbergen, 217* — on a method of measuring the heights of cliffs* 
288 — on the temperature of the Arctic Seas, 360. 
Sea-charts, 277* 
Sea-horse found in the Hebrides, 389. 
Sea-water, potash in, 325. 
Sepia colmr from peat, I90. 
Sertularia gelatinosa of Pallas, observations on, 82. 
Shetland, account of the rocks of, 67* 
Silh of the pinna marina, I9I. 
Simia, new species of, 181. 
Singraula, quarry of corundum in, 305. 
Slide of Alpnach, account of, 110. — ^notice of its destruction, 11$, 
Slip, Mr Morton’s, for hauling vessels out of the water, 125. 
Snow in Rome, 382. 
Society of Arts in Edinburgh, I93. 
Solar eclipse in 1820, 379, 
Sound, on the nafure of, 374. 
Spines on the wings of birds, I90. 
Spitzbergen, seven icebergs of, 217. 
Springs, cold, account of rocks formed by, S07. 
Starch, experiments on the decomposition of, 382. 
Steam-engine, history of Mr Watt’s improvement on, 1. 
