

1 





i 



t! 





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Ch. III.] 



T AUG IONL— LEHMAN. 



59 



whatever may be the defects of many of his views 



it is no 



controverted that the present continents _ are of 



The doctrine is as firmly established as 



longer 

 secondary origin. 



the earth's rotation on its axis 



and that the land now 



Lilt; CcL-L UU. O a\_/ul4Ju-»-w" ~ — ' 



elevated above the level of the sea will not endure for ever, 

 is an opinion which gains gronnd daily, in proportion as we 

 enlarge onr experience of the changes now m progress. 



Targioni, 1 751. -Targioni, in his voluminous < Travels m 

 Tuscany 1751 and 1754,' laboured to fill up the sketch of 

 the oology of that region left by Steno sixty years before. 

 Notwithstanding a want of arrangement and condensation 

 in his memoirs, they contained a rich store of faithful obser- 

 vations. He has not indulged in many general views, but 

 in regard to the origin of valleys, he was opposed to the 

 theory of Buffon, who attributed them principally to sub- 

 marine currents. The Tuscan naturalist laboured to show 

 that both the larger and smaller valleys of the Apennines 

 were excavated by rivers and floods, caused by the bursting 

 of the barriers of lakes, after the retreat of the ocean. 

 also maintained that the elephants and other quadrupeds, 

 so frequent in the lacustrine and alluvial deposits of Italy, 

 had inhabited that peninsula ; and had not been transported 

 thither, as some had conceived, m 

 nor by what they were pleased to term < a catastrophe ot 



nn tiirP 



Lehman, 1756.-In the year 1756 the treatise of Lehman, 

 a German mineralogist, and director of the Prussian mines, 

 appeared, who also divided mountains into three classes 



He 



Hannibal 



the first, those formed with the world, and prior to the 

 creation of animals, and which 



ments 



other rocks ; the second class, those which resulted from the 

 partial destruction of the primary rocks by a general revolu- 

 tion ; and a third class, resulting from local revolutions, and 



in part from the deluge of Noah. 



A Trench translation of this work appeared in 1759, in the 

 preface of which, the translator displays very enlightened 

 views respecting the operations of earthquakes, as well as Oj. 

 the aqueous causes.* 



* Essai (Tune Hist. Nat. des Couches de la Terre, 1759. 



