INDEX. 199 



Thorina, compound nature of, demonstrated, xx. 391 

 Thouin (M.), on a mode of planting through trees, xviii. 409 

 Thunder-storms, observations on the periodical returns of, iii. 390. 



xvi. 39a 

 TiARCK (Dr.), longitude of Madeira and Falmouth determined 



by, xvii, 270 

 Tide-gauge, new, description of, xvi. 348 



extracts relative to the theory of, xvii. 295 



Tiger hunt in India described, vii. 266 

 Timbuctoo, remarks on the state of, vii. 333 

 Time-keeper (new), notice of, vii. 369 

 Time-table, for reducing sidereal to mean, xii. 167 



— of conjunction in right ascension, an easy method of 

 computing, from an observed occultation, xv. 360 



— indicated by any number of chronometers, an easy me- 

 thod of comparing with the given time at a certain station, 

 xvii. 315 



Tin, nature and properties of, v. 299 



and lead, mutual precipitation of, vi. 363 



increased weight when calcined, accounted for, xii. 295 



mines in the isle of Banca, how wrought, ii, 191 



plate, manufacture of, described, vii. 141 



Tinning, process of, described, vii. 145 



Tissues, how rendered incombustible, xii. 413 



Titanic acid, separation of, from the oxide of iron, xx. 176 



Titanium, found in iron ore, viii. 167 



— analysis of a compact ore of, xii. 265 



. process for analyzing the oxide of, xiii. 226. (Metallic) 



notice of, xiv. 441 

 combinations of, with oxygen and sulphur, xvi. 07. 



Experiments and observations on metallic, 326 



on the apparent magnetism of, xvii. 129 



on the various combinations of, xviii- 174 



the presence of, in mica, confirmed, 392. xix. 1/J7. 



Analysis of the chloride of, 156 



(metallic), found in iron furnaces, xx. 17« 



