INDEX. 427 
Silk-worm, on the extraordinary length of a line of one, 410. 
Silliman, Professor, on the fusion of charcoal, 187- 
Skulls, on human ones found in Germany, 408. 
Snow blindness described, 259. 
Sound, on the velocity of, 184,— sounds in hydrogen gas, 184. 
Specula , on a machine for grinding and polishing, 891 1 
Sprengel, Dr, on the life and writings of Olaus Swartz, 1 7- 
Springs, on the temperature of, 396. 
Steam-boats in Italy, 202. 
Steam-engine, on Perkins' new one, 186, 898. 
Steam-ships building by Government, 899- 
Steel, on Mr Barton’s method of ornamenting it, 128. 
Steinhausser’s method of making artificial magnets, 183. 
Storm, singular one at Enghien described, 1 85. 
Strontian, test for, 188. 
Swartz , Olaus, memoir of the life and writings of, 17* 
T 
Tabular spar, analysis of, 188. 
Temperature of springs, 396, — mean temperature of Cape Town, 396. 
Thermometers, on variations in the bulbs of, 397- 
Toad found in a solid rock, 402. — economy of the, 411. 
Tongue, on the remarkable irritability of the, 26 1. 
Topaz, Brazilian, on the distribution of the colouring matter, and on 
certain peculiarities in its structure, 389. 
Torrey, Dr, on the green oxide of zinc, 403. 
Traitl Island in Greenland described, 359* 
Travels, scientific and literary, 202,-— of Dr Spix and Martius’s in 
Brazil, 203. 
Tufas, calcareous, of Hungary described, 29. 
Turquoise of Persia, 304. 
Tutenag of China, remarks upon it, 9 1 . 
V 
Violet rays, on the magnetism of the, 183. 
W 
Walnut trees, on the method of ringing them, 194. 
Waterfalls at Rewah described, 83. 
Webster, Dr, on a cavern of lava in St Michael's, 41 6. 
Wernerian Society, proceedings of the, 180, 386. 
Weiss, Professor, on the distribution of the different systems of cry- 
stallisation, 103. 
Whew ell, Mr W. on the rotation of bodies, 389,-— on two mechanical 
problems, 39 0. 
While copper of China, remarks upon it, 91 . 
Whitelaw, Mr David, on a new escapement by, 27. 
Wire-gauge recommended by the Society of Arts, 418. 
Wollaston, Dr, his test for magnesia, 187, 
X 
Xanthodpia of jaundiced persons described, 264. 
Z 
Zinc, on the green oxide of, 403. 
