108 



INDEX. 



Velay, ancient'alluviums covered by lava 



at different heights in, 262 

 Vertical and inclined strata, great line of, 

 from the Isle of Wight to Dieppe, 315 T 

 Vesuvius, dikes of, 121 



channels formed by the flowing of 



lava from, in 1779, 122 

 and Somma, difference in their com- 

 position, 120 

 Vichy, tertiary oolitic limestone of, 232 



dip of the lacustrine strata at, 233 



Vienna, tertiary formations of, 21, 212 

 age of the tertiary strata of, 214 

 . , basin, fossil shells of the see Table, 



Appendix I. 

 Vigolano, gypsum interstratified with sub- 



Apennine marls at, 159 

 Villasmonde, shells found in limestone at, 65 



list of fossil shells from Appendix 



II., 54 

 Villefranche, bay of, tertiary strata found 



near the, 135 



Vinegar river, sulphuric and muriatic acids, 

 and oxide of iron, in the waters of the, 

 252 

 Virlet, M., on the tertiary strata of the 



Morea, 170 

 Viterbo, volcanic tuffs and sub-Apennine 



marls alternating at, 159 

 .. age of the volcanic rocks of, 183 

 Viviani, Professor, on the character of the 



Sicilian flora, 115 



on the tertiary strata of Genoa, 166 

 Vizzini, junction of inclined tuff and hori- 

 zontal limestone near see diagram No. 

 8,70 

 changes caused by a dike of lava in 



argillaceous strata at, 70 

 . a bed of oysters between two lava- 

 currents at, 73 

 Volcanic breccias in Auvergne, how 



formed, 259 



Volcanic conglomerates of the Val di Noto, 

 73 



. now forming on the shores of Catania 

 and Ischia, 73 



Volcanic dikes, strata altered by, 70, 368 

 Volcanic district of Catalonia, superposition 

 of rocks in the see wood-cut No. 47, 

 192 



Volcanic line?, modern, not parallel, 349 

 Volcanic region of Naples, changes which 

 it has undergone during the last 2000 

 years, 118 



Volcanic rocks, distinction between sedi- 

 mentary and, 10 

 . relative age of, how determined, 36 



of the Val di Noto, 68 



. of Campania, their age, 126 

 . of central France, 257 



secondary, of many different ages, 



333 



Volcanic rocks, distinction between i>lu- 



tonic and, 359 

 Volcanos, mode of computing the age of, 



sometimes inactive for centuries, 98 



of Olot, in Catalonia, described- 

 see Frontispiece, 183 

 extinct, of Sardinia, 193 



of the Lower Rhine and the Eifel, 



193 



the result of successive accumula- 

 tion, 240 



attempt to divide them into ante- 

 diluvian and post-diluvian, 268 



Volhynia, tertiary formations of, 215 



Voltz, M., on the loess of the Rhine, 151 



Von Buch, M., on the Eifel, 201 



on the tertiary formations of Volhynia 



and Podolia, 215 



on the general range of volcanic lines 



over the globe, 349 



Von Dechen, M., on the volcanic district of 

 the Lower Rhine, 201 



on the Hartz mountains, 346 



his objections to the theory of M. de 



Beaumont, 346, 347 



on the Cornish granite veins see 



wood-cut No. 87, 355 



Von Oeynhausen, his map of the Eifel dis- 

 trict, 193 



on the volcanic district of the Rhine. 



201 



on the granite veins of Cornwall 



see wood-cut No. 87, 355 ,, 



Walton, section of shelly crag near see 



wood-cut No. 31, 174 

 lamination of sand and loam near- 

 see wood-cut No. 34, 175 

 Warburton, Mr., on the Bagshot sand, 280 

 Watt, Gregory, his experiments on melted 



rocks, 124,372 

 Weald, denudation of the valley of the. 



285 

 secondary rocks of the, divisible into 



five groups, 286 

 section of the valley of the see 



wood-cuts Nos. 63 and 64, 287, 288 



clay, its composition, 286 



gradual rise and degradation of the 



rocks of the, 289 



alluvium of the valley of the, 295 

 extent of denudation in the valley of 



the, 303, 313 



Wealden, secondary group, called the, 325 

 organic remains of the, 325 



its great extent and thickness, 329j . 



how deposited, 329 



Webster, Mr., on the geology of the Isle of 



Wight, 18, 315 



on the tertiary formations of the 



London and Hampshire basins, 278, 280 



