INDEX. 119 



Levity, non-existent in nature, xi. 8 1 , 



Levy (Mr.), observations of, on the crystalline forms of artificial 

 salts, XV. 282 



Letden (Dr.), sketch of Borneo by, ii. 340 



Leyden jar, improvement in the construction of, xvii. 162 



Lichens, observations on the growth of, ii. 54 



■ » or river- worts, construction and fructification of, vi. 218 



LiEBEG (Dr.), experiments of, on fulminating silver and mercury, 

 xvii. 153; and on fulminic acid and fulminates, 386 



Life, on the relative and absolute duration of, iij. 40. Regulation 

 of the Code Napoleon on this point, ib. Defects of the English 

 law thereon, 41. Uncertainty of the signs of, 44 



boat, new, notice of, vi. 351 



tenacity of in larvae, xx. 189 



Light, properties of, i. 98. Notice of some new discoveries re- 

 specting, 297 



effects of on vegetation, ii. 48. Experiments on, by Dr. 



Brewster, 207. Decomposition of by simple reflection, 211 



evolution of, by the expansion of oxygen, vii. 384. Mag- 



netism by, 398 



evolved by pressure, xv. 368 



influence of, on the purple tint of plate-glass, xvi. 164. 



xix. 341 



■ effects of, on the colour of sodalite, xviii. 179. Of incan- 



descent bodies, 384 

 and heat from terrestrial sources, observations on, xix. 



45, 213. Produced during crystallization, 341 



of haloes, polarized state of, xx. 167 



houses, new, notice of, vi. 136. vii. 170. x. 450. Sug- 



gested improvements in, xx. 376 , 



Lighting explosive atmospheres in coal-mines. Sir H. Davy's con- 

 trivance for, i. 1. Proofs of its utility, 131, 302 



Lightning, straw a conductor for, ix. 199 



discharge of, through a bad conductor, x. 460 



effect of, xii. 414 



• case of palsy cured by, xiii. 419 



■ electro-magnetic effect of, xiv. 442 



