NOTES. 



Saussure and Earl Minto, in the Abhandlungen der Academic der Wiss. zu 

 Berlin aus den J. 1822 and 1823, S. 30. 



(^ p. 222. Pimelodes cyclopum, vide Humboldt, Recueil d' Observations 

 de Zoologie et d' Anatomic comparee, T. i. pp. 21 25. 



C 221 ) p. 224. Leop. von Buch, in Poggend. Ann. Bd. xxxvii. S. 179. 



C 222 ) p. 224. On the chemical origin of specular iron in volcanic masses, 

 see Mitscherlich, in Poggend. Ann. Bd. xv. S. 630 ; and on the disengage- 

 ment of hydrochloric acid gas in craters, see Gay-Lussac, in the Annales de 

 Chimie et de Physique, T. xxil p. 423. 



(^ p. 226. See the fine experiments on the cooling of masses of stone, 

 in Btschofs Warmelehre, S. 384, 443, 500512. 



P) p. 226. Berzelius and Wdhler, in Poggend. Annalen, Bd. i. S. 221, 

 and Bd. xi. S. 146 ; Gay-Lussac, in the Annales de Chimie, T. xiiii. p. 422 , 

 Bischof, Reasons against the Chemical Theory ol Volcanoes, in the English 

 edition of his Warmelehre, pp. 297309. 



(^ p. 227. In Plato's geognostical ideas, as developed in the Phscdon, 

 the Pyriphlegethon plays nearly the same part, in respect to the activity of 

 volcanoes, as that which we now assign to the internal heat of the globe, 

 increasing with increasing depth, and to the state of fusion ot the deeper 

 strata. (Phtedon, ed Ast. pp. 603 and 607, Annot. pp. 808 and 817). 

 " Within and around the Earth there are subterranean channels of various 

 magnitudes. Water flows through them abundantly, as do currents of fire, 

 and streams of liquid mud, more or less impure, like the flow of mud which, 

 in Sicily, precedes the issuing forth of torrents of fire, both alike overwhelming 

 every thing in their path. The Pyriphlegethon pours itself into a wide space, 

 where a strong fire burns fiercely, and it there forms a lake larger than our 

 sea, in which the water and mud are always boiling; and, re-issuing thence, 

 it rolls its troubled and muddy waves around the earth." This river of molten 

 earth and mud is so far the general source of volcanic phenomena, that Plato 

 says expressly, in his continuation, " Such is the Pyriphlegethon, of which 

 the fiery currents (o< pvctKes), wherever they are found on the earth (OTTTJ av 

 Tux<rau TTJS 7775), are a part. Volcanic scoriae and currents of lava are 

 therefore regarded as parts of the Pyriphlegethon itself, or of a subterranean 

 molten mass, in coatinued motion, in the interior of the earth. That ot 

 pvafces signifies lava currents, and not " fire-ejecting mountains," as Schneider, 

 Passow, and Schleiermacher would suppose, is evident from many passages, of 

 which part have been brought together by Ukert, (Gcogr. der Griechen und 



