INDEX TO VOL. V. 



Anion on volcanic phenomena in Ghilan,' 

 169 ; his views on the Caucasian mount-! 

 ain system, 201, 3S3; analysis of the 

 Chimborazo rock, 431. 



Aconcagua, volcano of, measurement of, 

 273. 



Acosta on the volcancitos of Turbaco, 205. 



Adams, Mount, a volcano, 390. 



iEnaria, the island of Apes, 252. 



iEoliis, residence of, on Strongyle, 244. 



./Etna, eruptions of, usually occur within a 

 space of six years, 243; periods of its 

 greatest activity, 244; height to which 

 ejected matters attain, 251; its trach- 

 ytes, 434. 



Africa, determination of the magnetic 

 equator in, by Sabine, 102 ; its transla- 

 tion, 1 04 ; snowy mountains in, 333 ; vol- 

 canoes in, 332 ; their small number, 334. 



African magnetic node, its varying posi- 

 tion, 102. 



Agaschagokh, island of, 343. 



Agreeable odor diffused from certain vol- 

 canoes, 219. 



Agua, Volcan de, described, 262. 



Airy, density of the earth determined by, 

 35 ; on terrestrial magnetism, 79. 



Alaid, great eruptions of the volcano on 

 the isle of, 349. 



Albite, 438. 



Aleutian islands, numerous volcanoes in, 

 347. 



Alps, temperature of springs in the, 184. 



Amei'ica. See Central America, Chili, 

 Mexico, Northwest America, Peru and 

 Bolivia, Rocky Mountains, South Sea. 



Ampere on the cause of earthquakes, 162. 



Ampolletas, 57. 



Amsterdam, volcanic island of, 3G0. 



Anahuac, series of volcanoes of, 266. 



Anaxagoras, maxim of, verified, 11. 



Andaman isles, volcanic phenomena in the, 

 359. 



Andes, large spaces in the chain of, desti- 

 tute of volcanoes, 267 ; groups and dis- 

 tances, 26S ; special direction of the 

 three Cordilleras, 276. 



Andesite, 437, 439. 



Andrea Bianco, his early charts exhibit 



the magnetic variation, 55. 

 Anemasite, 446. 



Annular valleys, 221. 

 Ansango, lake of, 313. 

 Ansogorri, Father Joaquin, his description 



of the rise of the volcano Jorullo, 292. 

 Ant-hills in the Rocky Mountains, their 



remarkable construction, 443. 

 Antilles, Little, volcanoes of the, described, 

 394. 



Antisana, the colossal mountain, described, 

 311; its dikes, 312; lakes, 313. 



Antuco, volcano of, 273. 



Aphron, the northern pole of the mag- 

 netic needle, 54. 



Apparatus employed by Humboldt for his 

 453 determinations of height in the New 

 World, 428. 



Arabia, laVa eruptions in, 336. 



Arago on magnetic inclination, 105; his 

 series of magnetic observations, 75. 



Aiarat, as a volcano, 339. 



Arare, crater of, SOS. 



Arequipa, volcano of, 270. 



Argpeus, the volcano, 237. 



Arimer, country of the, 252. 



Aristotle on the fundamental principles of 

 nature, 9; volcanic phenomenon upon 

 Hiera described by, 219. 



Arran, volcanic phenomena in, 329. 



Artesian wells, Walferdin's observations 

 on, 38. 



Ascension, volcanic phenomena of the isl- 

 and of, 331. 



Asia, situation of the principal volcanoes 

 in, 2S1 ; volcanoes of the western and 

 central parts, 834 ; of Kamtschatka, 340 ; 

 of the islands of Eastern Asia, 344 ; of 

 the islands of Southern Asia, 354; of the 

 Indian Ocean, 35S. 



Atlantic Ocean, volcanoes of the islands 

 of the, 330; presumed submarine vol- 

 cano, 332. 



Atlantis of Solon, 173. 



Atolls, or lagoon reefs, 363. 



Attraction of the magnet known to the 

 Greeks and Romans, 51. 



Augite, 443. 



Aurora Borealis, 147 ; observations of the 

 black segment, 148; colors observed in 

 high latitudes, 149 ; accompanying fleecy 

 clouds, 150; influence on terrestrial mag- 

 netism, 152 ; obsei - vations at Berlin and 

 at Edinburgh, 153. 



Auvergne, extinct volcanoes of, 227, 263. 



Azores, craters of elevation in the, 217; 

 the volcano of Pico, 236. 



Azufral de Quindiu, Humboldt's visit tc 

 the, 211 ; change of temperature ob- 

 served by Boussingault, 212. 



Baily on the density of the earth, 34. 



Baker, Mount, a volcano, 390. 



Banda, a volcanic island, 357. 



Barba, the volcano, described, 259. 



Barile, earthquake at, 167. 



Barrancos on the slopes of volcanoes, 



287. 

 Barren Island, one of the Andamans, ap- 



