3S6 Baron Humboldt on the Structure and Action of 



shine on the west, when outraged humanity shall no longer 

 groan beneath the savage barbarity of the Ottomans. 



I bring forward the geographical proximity of these numerous 

 phenomena, to shew that the basin of the Mediterranean, with 

 i^s islands, is capable of presenting to the attentive observer all 

 ^ that has recently been discovered, under various forms, in South 

 America, in TenerifFe, or in the Aleutian Isles, in the vicinity 

 of the polar regions. The objects to be observed were united 

 together ; but travels into distant regions, and comparisons of 

 extensive countries in Europe and out of it, were necessary for 

 clearly shewing the mutual resemblance of volcanic phenomena, 

 and their dependence upon one another. 



Common language, which often gives consistency and dura- 

 tion to ideas arising from the most erroneous views of things, 

 but which also frequently indicates the truth instinctively, 

 gives the name of Volcanic to all the eruptions of subterranean 

 fires and melted substances ; to the columns of smoke and va- 

 pour which issue from the heart of rocks, as at Colares, after the 

 great earthquake at Lisbon ; to the salses or cones of clay which 

 vomit mud, asphaltes, and hydrogen, as at Girgenti, in Sicily, 

 and at Turbaco, in South America ; to the hot springs of the 

 Geyser, which, impelled by elastic vapours, rise to an immense 

 height ; in a word, to all the effects of the mighty powers of na- 

 ture, which have their seat in the interior of our planet. In 

 central America, or in the country of Guatemala, and in the 

 Philippine Isles, the natives make an essential difference between 

 water volcanoes and fire volcanoes (volcanes de aguaydefuego). 

 By the former name they designate the mountains, from which, 

 amid violent earthquakes, subterranean waters issue from time 

 to time. 



Without denying the connection of the phenomena just men- 

 tioned, it would yet appear expedient to give a more precise lan- 

 guage to the physical and oryctognostical department of geo- 

 gnosy, in order to prevent the application of the name of Volcano, 

 sometimes to a mountain which is terminated by a permanent 

 furnace, and sometimes to each subterranean cause of volcanic 

 phenomena. In the present state of the terrestrial globe, the 

 most common form of volcanoes, in all parts of the world, is 

 that of an isolated cone, such as Vesuvius, Etna, the Peak of 



