212 HEROES OF SCIENCE. 



into stagnant pools. During earthquakes some 

 springs have been closed up, and new ones have 

 broken out. Rivers have deserted their channels, 

 and have been reborn elsewhere ; as the Erasinus, 

 in Greece, and Mysius, in Asia. The waters of 

 some rivers, formerly sweet, have become bitter, as 

 those of Anigrus, in Greece. Islands have become 

 connected with the main land, by the growth of 

 deltas and new deposits. Peninsulas have been 

 divided from the main land, and have become 

 islands, as Leucadia ; and according to tradition, 

 Sicily, the sea having carried away the isthmus. 

 Land has been submerged by earthquakes. The 

 Grecian cities of Helice and Burris, for example, 

 are to be seen under the sea, with their walls 

 inclined. Plains have been upheaved into hills by 

 the confined air seeking vent, as at Troezene, in the 

 Peloponnesus, There are streams which have a 

 petrifying power, and convert the substances which 

 they touch into marble. Volcano vents shift their 

 positions. There was a time when Etna was not a 

 burning mountain, and the time will come when 

 it will cease to burn ; whether it be that some 

 caverns be closed up by the movements of the 

 earth and others opened, or whether the fuel is 

 finally exhausted." 



Of course there are several errors in these state- 

 ments, and especially those which relate to the 

 causes of volcanic vents are absurd. Pythagoras also 

 noticed the changes in the animal kingdoms, such 

 as the metamorphoses of insects. Besides being 



