TRUE VOLCANOES. 445 



(especially in the leucite ophyrs of the Somma), in the Arso 

 of Ischia, in the eruption of 1301, mixed with glassy feld- 

 spar, brown mica, green augite, and magnetic iron, in the 

 volcanoes of the Eifel, which emit lava streams (for example, 

 in the Mosenberge, westward of Manderscheid),* and in the 

 southeastern portion of TenerhTe, in the lava eruption of 

 Guimar in the year 1704, I have also searched for it very 

 diligently, but in vain, in the trachytes of the volcanoes of 

 Mexico, New Granada, and Quito. Our Berlin collections 

 contain sixty-eight specimens of trachyte of the four volca- 

 noes, Tungurahua, Antisana, Chimborazo, and Pichincha 

 alone, forty-eight of which were contributed by me and twen- 

 ty by Boussingault.f In the basalt formations of the New 

 World olivin, along with augite, is as abundant as in Europe ; 

 but the black, basaltic trachyte of Yana Urcu, near Calpi, at 

 the foot of the Chimborazo, J as well as those enigmatical tra- 



Glas, is the only one which contains olivin (Descr. des lies Canaries, 

 p. 207). The supposition that the eruption of 1704 was the first which 

 had taken place since the conquest of the Canary Islands, at the 

 end of the loth century, has been shown by rae in another place (Ex- 

 amen Critique cle VHistoire tie la Geographic, t. hi., p. 143-146) to be 

 erroneous. Columbus saw the eruption of fire on Teneriffe, at the 

 time of his first voyage of discovery, on the nights of the 21st to the 

 25th of August, when he went in search of Dona Beatriz de Bobadilla, 

 of the Gran Canaria. It is thus noticed in the admiral's journal, un- 

 der the Rubric of " Jueves, 9 de Agosto," which contains notices up to 

 the 2d of September — " Vieron salir gran fuego de la Sierra de la Isla 

 de Tenerife, que es muy alta en gran manera" — "they saw a great 

 deal of fire rising with a grand appearance out of the mountain of the 

 island of Teneriffe, which is very high ;" Navarrete, Col. de los Viages 

 de los EspaTwles, t. i., p. 5. The lady above named must not be con- 

 founded with Dofia Beatriz Henriquez of Cordova — the mother of his 

 illegitimate son, the learned Don Fernando Colon, the historian of his 

 father — whose pregnancy in the year 1488 so materially contributed to 

 detain Columbus in Spain, and to lead to the discovery of the New 

 World being made on account of Castile and Leon, and not for 

 Portugal, France, or England (see my Examen Critique, t. iii., p. 350, 

 and 367). * Cosmos, see above, p. 222. 



f A considerable portion of the minerals collected during my Ameri- 

 can expedition has been sent to the Spanish Mineral Cabinet, to the 

 King of Etruria, to England, and to France. I do not refer to the geo- 

 logical and botanical collections which my worthy friend and fellow- 

 laborer, Bonpland, possesses, with the two-fold right of self-collection 

 and self-discovery. This extensive dispersion of the material (which, 

 from the very exact account given of the places in which they origin- 

 ated, does not prevent the maintenance of the groups in their geograph- 

 ical relations) has this advantage, that it facilitates the most compre- 

 hensive and exact definition of those minerals whose substantial and 

 habitual association characterizes the different kinds of rocks. 



I Humboldt, Kleinere Schrijlen, bd. i., s. 139. 



