OTID. 21 



The change of marshes into dry ground, and of dry ground 

 to stagnant pools. 



The issuing of springs during earthquakes, and the drying 

 up of others. 



The desertion of their ancient beds by rivers, and their 

 re-appearance in new channels. 



The uniting of islands with mainlands by the growth of 

 deltas and new deposits. 



The insulation of peninsulas by the destruction of the 

 isthmus which previously connected them with the mainland. 



The submergence of land by earthquakes, and the phe- 

 nomenon of cities appearing beneath a lake. 



The elevation of plains into hills. 



The petrifying power of certain streams, which convert 

 the substances immersed in them to marble. 



The shifting of the site of volcanic action. " There was a 

 time," says the poet, " when Etna was not a burning moun- 

 tain, and a time will arrive when it will cease to burn ! " 



This celebrated description has attracted much attention ; 

 and the following lines, which commence it, have been quoted 

 in almost every introductory work on geology : 



" Vidi ego quod fuerat quondam solidissima tellus, 

 Esse fretum ; vidi factas ex sequore terras. 

 Et procul a pelago conchae jacuere marinse, 

 Et vetus inventa est in montibus anchora summis j 

 Quodque fuit campus, vallem decursus aquarum 

 Fecit, et eluvie mons est deductus in aequor." 



The truth of the whole narrative will be generally acknow- 

 ledged, with the exception possibly of the anchor found on 

 the summit of the hills, which may be regarded as a mere 

 poetic fable ; like the beautiful but imaginary narrative of 

 the destruction of the phoenix by fire, and its resuscitation 

 from its ashes ; or the explanation of volcanic agency, by 

 the assumption that the earth is an animal, and that its 

 mines of sulphur taking fire, consume its internal unctuous 

 substances, till, these being exhausted, the flames die out for 

 want of animal fuel ! The last line, explaining the disinte- 

 gration of mountain-masses, and their transport to the bed 

 of the ocean by aqueous agency, has been noticed by Sir C. 

 Lyell as somewhat obscure. May it be permitted to suppose 



