524 



INDEX. 



Vibrations of musical strings, 156. 



of columns of air in pipes, 158. 



of elastic solids, 160 et seq. 



, sympathetic, 1, 164. 



of polarised light, 203. Note 201. 



Volcanic action, 281 et seq. 



, theories of, 285. 



Volta, Professor, his construction of the 



Voltaic pile, 330. 

 Volta-electric induction, 367- 

 Voltaic battery, 332. 



electricity, discovery of, 330. 



, properties of, 334. 



, luminous effects of, 335. 



, chemical effects of, 336. 



, transference of, 337. 



, composition by, 338. 



, effects of, on the senses, 339. 



Volume, 65. 



W. 



Water, decomposition and composition 

 of, 337, 375, 383. 



of crystallization, 124. 



a conductor of sound, 150. 



, rotation of, 357. 



Week, the antiquity of, 96. 



Weight of the atmosphere, 131. 



at the surfaces of the sun and 



planets, 65. 



Weights and measures, 105. 



Wheatstone, Professor, his musical in- 

 struments, 160. His experiments on 

 vibrating surfaces, 162. On the trans- 

 mission of sound, 167. On resonance, 



169. On the velocity of the electri r 

 fluid, 323. On the spectrum of the 

 Voltaic spark, 336. 



Willis, Mr., his speaking-reed, 169. 



Wollaston, Dr., on the extent of the 

 atmosphere, 120. On the extent of 

 hearing, 146. On refraction, 175. 

 Discovers the chemical rays and dark 

 lines of the solar spectrum, 182, 225. 

 On rotatory motion by the electro- 

 magnetic force, 356. On the light of 

 the celestial bodies, 430. 



V. 



Year, civil or tropical, and sidereal * 

 years, 93 et seq. 



Young, Dr. Thomas, on the compres- 

 sion of substances, 88. His hiero- 

 glyphic researches, 100. On capilhiry 

 attraction, 128. On the love of har- 

 mony, 158. Establishes the undula- 

 tory theory of light, 190. On the in- 

 terference of light, 195. On radiant 

 heat, 264. 



Z. 



Zodiacal light, supposed to be the at- 

 mosphere of the sun, 436; or, accord- 

 ing to La Place and Professor Olmsted, 

 a nebulous body revolving in the plane 

 of the solar equator, 449. 



Zones of instability discovered by Le 

 Verrier, 24, 25. 



THE END. 



G. Woodfall and Son, Printers, Angel Court, Skinner Street, London. 



