236 COSMOS. 



The different volcanoes over the Earth's surface, when 

 they are considered independently of all climatic differences, 

 are acutely and characteristically classified as central and 

 linear volcanoes. Under the first name are comprised those 

 which constitute the central point of many active mouths of 



there in abundance, also much fire and large streams of fire, and streams 

 of moist mud (some purer, and others more filthy), like those in Sicih-, 

 consisting of mud and fire, preceding the great eruption. These streams 

 fill all places that fall in the way of their course. Pyriphlegethou 

 flows forth into an extensive district burning with a fierce fire, where it 

 forms a lake larger than our sea, boiling with water and mud. From 

 thence it moves in circles round the earth, turbid and muddy." This 

 stream of molten earth and mud is so much the general cause of vol- 

 canic phenomena, that Plato expressly adds, "thus is Pyriphlegethon 

 constituted, from which also the streams of fire (ol pvaKto), wherever they 

 reach the earth (OTT/; civ TV\WGI TTJQ jr)Q), inflate such parts (detached 

 fragments)." Volcanic scoriae and lava-streams are therefore portions of 

 Pyriphlegethon itself, portions of the subterranean molten and ever- 

 undulating mass. That ol p?;a/ceare lava-streams, and not, as Schneider, 

 Passow, and Schleiermachcr will have it, " fire-vomiting mountains," is 

 clear enough from many passages, some of which have been collected by 

 Ukert (Geogr. der Griechen und Homer, th. ii., s. 200) ; pva% is the 

 volcanic phenomenon in reference to its most striking characteristic, the 

 lava stream. Hence the expression, the pvctKts of ..Etna. Aristot. 

 Mirab. Ausc., t. ii. p. 833; sect. 38, Bekker; Thucyd., iii. 116; Theo- 

 phrast., Be Lap., 22, p. 427, Schneider; Diod. v., 6, and xiv, 59, 

 where arc the remarkable words, " Many places near the sea, in the 

 neighbourhood of Etna, were levelled to the ground, VTTO rov KaXovpsvov 

 PVO.KOQ;" Strabo, vi. p. 269, xiii. p. 628, and where there is a notice of 

 the celebrated burning mud of the Lelantine plains, in Euboea, i. p. 58, 

 Casaub. ; and Appian. De Bella Givili, v. 114. The blame which Aris- 

 totle throws on the geognostical fantasies of the Phcedo (Meteor., ii., 

 2, 19), is especially applied to the sources of the rivers flowing over the 

 earth's surface. The distinct statement of Plato, that " in Sicily erup- 

 tions of wet mud precede the glowing ('ava) stream," is very remarkable. 

 Observations on Etna could not have led to such a statement, unless 

 pumice and ashes, formed into a mud-like mass by admixture with 

 melted snow and water, during the volcano-electric storm in the crater 

 of eruption, were mistaken for ejected mud. It is more probable that 

 Plato's streams of moist mud (vypov TrjjXou Trorajuoi) originated in a 

 faint recollection of the Salses (mud volcanoes) of Agrigentum, which, 

 as I have already mentioned, eject argillaceous mud with a loud noise. 

 It is much to be regretted, in reference to this subject, that the 

 work of Theophrastus Trtpt pvaicog rov tv SiKeXicr, On the Volcanic 

 Stream in Sicily, to which Diog. Laert., v. 49, refers, has not come 

 down to us. 



