THEORY OF THE EARTH. 4& 



idea of the propriety of clearing them up before 

 constructing their systems. 



Reason for which the Conditions of the Problem have- 

 been neglected. 



The reason of this strange procedure will be 

 discovered, when we reflect, that all geologists 

 have hitherto been, either mere cabinet natura- 

 lists, who had themselves paid little atttention 

 to the structure of mountains, or mere mineralo- 

 gists, who had not studied in sufficient detail the 

 innumerable varieties of animals, and the infinite 

 complication of their various parts. The former 

 of these have only constructed systems : the latter 

 have furnished excellent observations, and have 

 laid the foundation of true geological science ; but 

 have been unable to complete the edifice. 



Progress of Mineral Geology. 



The purely mineral part of the great problem 

 of the Theory of the Earth has been investigated 

 with admirable care by Saussure, and has been 

 since carried to an astonishing degree of develop- 

 ment by Werner, and by the numerous enlight- 

 ened pupils of his school. 



The former of these celebrated men, by a la- 

 borious investigation of the most inaccessible dis- 

 tricts, continued for twenty years, in which he 

 examined the Alps on all sides, and penetrated 



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