26 Principles of Geology, 



ing a long period, the sea flowed rich in living beings over rocks 

 which contain no relics of life. At times tranquil, at intervals tu- 

 multuous, this ocean, perhaps of elevated temperature, even in the 

 northernmost regions, varied its deposits at different periods, yet pre- 

 served among them a general conformity of arrangement, from the 

 oldest to the most recent, and a similarity over large regions. The 

 aquatic animals and other remains, which are entombed in the earth, 

 exhibit a long series of beings, whose origin dates from some of the 

 earliest strata, and whose forms, differing according to the antiquity 

 of the rocks, successively come nearer and nearer to the modern 

 productions of the land and the ocean. During this process, at in- 

 tervals, vegetable forests swept into estuaries, or lakes, furnished the 

 materials of coal, and the intermitting action of submarine volcanoes 

 frequently broke the consolidated strata, and formed basaltic and 

 other overlying rocks. At times, too, more violent exertions, prob- 

 ably of the same cause, uplifted groups and ranges of mountains 

 wijh great disruption and dislocation. Operations of the same kind 

 are to this day continued, but so feebly,* that we commonly speak as 

 if the causes which concurred to produce the crust of our planet, had 

 ceased to exist. They appear, however, to have been gradually 

 weakened, and when the last series of the secondary beds, partly 

 marine, partly lacustrine, was deposited, a large portion of pre- 

 consolidated rocks become tenanted by land animals. But again 

 the waters returned and overflowed the inhabited world ; removed 

 rocks, excavated vallies, and destroyed the terrestrial inhabitants, 

 from whose anatomical construction, as displayed in their remains, it 

 inay be inferred that the antediluvian face of the earth was like our 

 own, diversified by lakes, and forests, and mountains. 



This transient flood retires from the desolated continents ; again 

 the forest is clothed with foliage 5 birds fly in air, and animals roam 

 the earth ; the mountains gather clouds, rain falls, the streams flow 

 down their new channels, the sea resumes its appointed boundary ; 

 cliffs are wasted, low shores are extended, vallies are filled up, vol- 

 canoes are in action ; nature revives again, and man, by contempla- 

 tion of the phenomena, reads the awful history of his birth-place, 

 gathers ideas of the immense agency exerted in the construction of 

 the earth, compares this planet with the other members of the solar 

 system, and views the solar system itself as only a small part of the 

 immeasurable works of God ! 



* Absuniptis per longum viribus avum. 



