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A SKETCH

OF A

PHYSICAL DESCRIPTION OF THE UNIVERSE.

BY

ALEXANDER VON HUMBOLDT.

TRANSLATED FROM THE GERMAN,

BY

E. C. OTTÉ AND W. S. DALLAS, F.L.S.

Naturæ vero rerum vis atque majestas in omnibus momentis fide caret, si quis modo partes

ejus ac non totam complectatur animo. Plin., Hist. Nat. lib. vii. c. 1.

VOL. V.

LONDON :

HENRY G. BOHN, YORK STREET, COVENT GADREN.

LONDON:

PRINTED BY HARRISON AND SONS,

ST MARTIN'S LANE, W.C.

Enumeration of all the active volcanoes in the Cordilleras, p. 285. Relation of the tracts without volcanoes to those abounding in them, p. 296, note 70 at 283; volcanoes in the North-west of America, to the north of the parallel of the Rio Gila, pp. 403—419; review of all the volcanoes not belonging to the New Continent, pp. 285—403; Europe, pp. 349—350; islands of the Atlantic Ocean, p. 351; Africa, p. 354; Asia; Continent, pp. 356—367 ; Thian-shan, pp. 358—359, 433, and notes 42—48; (peninsula of Kamtschatka, pp. 362—367); Eastern Asiatic Islands, p. 367; (island of Saghalin, Tarakai or Karafuto, notes 97—99, p. 305; volcanoes of Japan, p. 373 ; islands of Southern Asia, pp. 377–382;) Java, pp. 298–307. The Indian Ocean, pp. 382—388; the South sea, pp. 388_401.

Probable number of volcanoes on the globe, and their distribution on the

continents and islands

pp. 421-431

:

Distance of volcanic activity from the sea, pp. 295-6, 432-3. Regions of depression, pp: 431–436 ; Maars, Mine-funnels, pp. 231-3. Different modes in which solid masses may reach the surface from the interior of the earth, through a net-work of fissures in the corrugated soil, without the upheaval or construction of conical or dome-shaped piles, (basalt, phonolite, and some layers of pearl-stone and pumice, seem to owe their appearance above the surface, not to summit-craters, but to the effects of fissures). Even the effusions from volcanic summits do not in some lava-streams consist of a continuous fluidity, but of loose scoriæ, and even of a series of ejected blocks and rubbish; there are ejections of stones which have not all been glowing, pp. 308, 330, 332–337, 343–347, note 99 (p. 306) note 26 (page 335).

Mineralogical composition of the volcanic rock: generalisation of the term trachyte, p. 452 ; classification of the trachytes, according to their essential ingredients, into six groups or divisions in conformity with the definitions of Gustav Rose; and geographical distribution of these groups, pp. 453—467; The designations andesite and andesine, pp. 452—468, note, 471. Along with the characteristic ingredients of the trachyte-formations there are also unessential ingredients, the abundance or constant absence of which in volcanoes frequently very Dear each other, deserves great attention, p. 473; Mica, ibid; glassy felspar, p. 474; Hornblende and augite, p. 475; Leucite, p. 476; olivine, p. 477 ; obsidian, and the difference of opinion on the formation of pumice, p. 479; subterranean pumice beds, remote from volcanoes, at Zumbalica in the Cordilleras of Quito, at Huichapa in the Mexican Highland, and at Tschigem in the Caucasus, pp. 340–345. Diversity of the conditions under which the chemical processes of volcanicity proceed in the formation of the simple minerals and their association into trachytes, pp. 472, 473, 483.

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