THE GEOLOGICAL ThME-SCALE. 1 85 



from the chaotic fluid, the water became purer. Mountains 

 were conceived of as the local points of original crystallization 

 which drew to them, in the process, the minerals from the 

 general fluid. As the waters gradually withdrew by evaporation 

 and sinking into the interior caverns, they became clarified and 

 capable of supporting organic life. 



Kirwan says (p. 26) : " The level of the ancient ocean being 

 lowered to the height of 8,500 or 9,000 feet, then and not before, 

 it began to be peopled with fish." (Under the name fish he 

 included shell-fish, and all other petrifactions). The plains were 

 formed of depositions from the water of argillaceous, siliceous 

 and ferruginous particles, mingled with those derived by erosion 

 from the already protruding mountains. All the rocks above 

 the height mentioned, he observed, quoting from testimon}- of 

 numerous travelers, are lacking in fossils ; even the limestones 

 are crystalline or " primative " limestones and marbles. These 

 observations were cited in refutation of Buffon's "error" in 

 claiming that all limestones were derived from comminuted 

 shells. According to some authorities, primitive mountains 

 should include rocks of even less height than 8,000 feet, and the 

 occasional presence of fossils at a greater elevation was by them 

 accounted for by their transference to that elevation by the 

 deluge. This account of Kirwan's will suggest the way in which 

 the rock formation came at to be first called '' gebirge," or moun- 

 tains. Rocks were supposed to lie as they were originally 

 formed, and thus in classifying rocks the larger aggregates were 

 naturally mountain masses. As the conception of movements in 

 the earth's crust with folding and displacement came into the 

 science, the idea of classification and grouping of rocks was 

 retained, but that their grouping was based upon present massing 

 above the surface as mountains ceased to be accepted as truth. 

 In the German language the term " Gebirge" was retained, and 

 apparently with restricted meaning. Kirwan apparently trans- 

 lated the term directly into English as mountains. Formation 

 however took the place of inoimtain, as applied to rock classifica- 

 tion, in the early part of the centur3\ 



