246 COSMOS. 



times, of the totai extinction of the volcano of Mosyclilos,* 

 on the island sacred to Hephgestos (Vulcan), whose "high 

 whirling flames" were known to Sophocles ; and of the vol- 

 cano of Medina, which, according to Burckhardt, still continued 

 to pour out a stream of lava on the 2nd of November, 1276. 

 Every stage of volcanic activity, from its first origin to its 

 extinction, is characterised by peculiar products ; first by 

 ignited scorise, streams of lava consisting of trachyte, pyrox- 

 ene, and obsidian, and by rapilli and tuffaceous ashes, 

 accompanied by the development of large quantities of pure 

 aqueous vapour ; subsequently, when the volcano becomes a 

 solfatara, by aqueous vapours mixed with sulphuretted 

 hydrogen and carbonic acid gases ; and finally, when it is 

 completely cooled, by exhalations of carbonic acid alone. 

 There is a remarkable class of igneous mountains, which do 

 not eject lava, but merely devastating streams of hot water,f 

 impregnated with burning sulphur and rocks reduced to a 

 state of dust (as, for instance, the Galungung in Java) ; but 

 whether these mountains present a normal condition, or only 

 a certain transitory modification of the volcanic process, must 

 remain undecided until they are visited by geologists possessed 

 of a knowledge of chemistry in its present condition. 



I have endeavoured in the above remarks to furnish a 



* Sophocl., Pliiloct., v. 971 and 972. On the supposed epoch of 

 the extinction of the Lemnian fire in the time of Alexander, compare 

 Buttmann, in the Museum der Alterthumswissenschaft, bd. i. 1807, 

 s. 295 ; Bureau de la Halle, in Malte-Brun, Annales des Voyages, t. ix. 

 1809, p. 5; Ukert, in Bertuch, Geogr. Epliemeriden, bd. xxxix. 1812, 

 s. 361 ; Rhode, Res Lemnicce, 1829, p. 8 ; and Walter, Ueber A bnahme 

 der vulkan. Thatigkeit in historischen Zeiten, 1844, s. 24. The chart 

 of Lemnos, constructed by Choiseul, makes it extremely probable 

 that the extinct crater of Mosychlos, and the Island of Chryse, the 

 desert habitation of Philoctetes, (Otfried Mailer, Minyer, s. 300,) have 

 been long swallowed up by the sea. Reefs and shells, to the north-east 

 of Lemnos, still indicate the spot where the jEgean Sea once possessed 

 an active volcano like uEtna, Vesuvius, Stromboli, and Yolcano (in the 

 Lipari Isles). 



t Compare Reinwardt and Hoffmann, in Poggendorff's Annalen, 

 bd. xii. s. 607; Leop. von Buch, Descr. des lies Canaries, pp. 424-426. 

 The eruptions of argillaceous mud at Carguairazo, when that volcano 

 was destroyed in 1698, the Lodazales of Igualata, and the Moya of 

 Pelileo all on the table-land of Quito are volcanic phenomena of a 

 similar nature. 



