INTRODUCTION. 77 



increasing weight of the deposits, which were accumulating on 

 the ocean-floor, as well as the pressure caused by the repeated 

 crust-inthrows, at last caused the collapse of the lower tiers. 

 The sea-water rushed in to fill the depressed areas, and the 

 level of the ocean sank. This was called the first revolution 

 in De Luc's sequence of creative events. As the ocean sank, 

 the present continents and islands made their appearance; 

 plant seeds from the old continents were washed on the 

 strands of the emerging lands, and soon a rich vegetation 

 appeared. The fauna of the primitive ocean and lands in 

 some cases left descendants to people the new oceans and 

 lands, in other cases became extinct. 



The bones of the large tropical mammalia found in the 

 superficial strata of northern areas in the present continents 

 were believed by De Luc to be the transported remains of 

 extinct forms that had inhabited the older continents. Ac- 

 cording to De Luc, all known facts led to the conclusion that 

 the new continents, and generally the present configuration of 

 the earth, came into existence not more than 4000 years 

 ago. 



Four letters protesting against both Hutton and Playfair were 

 reprinted in a diffuse work by De Luc, entitled Elementary 

 Treatise of Geology. A large number of papers were con- 

 tributed to journals by De Luc ; but although he was a man 

 who was held in high respect and favour during his lifetime, 

 his papers have no permanent place in literature, and his 

 attacks on the great Scottish geologists were absolutely without 

 effect. 



Like De Luc, the Parisian mineralogist and physician, De 

 la Metherie, enjoyed considerable popularity among his con- 

 temporaries. His chief work, published at Paris in 1791, bore 

 again the title Theorie de la Terre. De la Metherie's work was 

 founded for the most part on Werner's teaching. Many of 

 the erroneous notions in De Maillet's Telliamed were revived 

 and new speculations attempted, but without any basis of 

 observation. According to De la Metherie, all mountains, 

 valleys, and plains took origin from the precipitation of 

 crystals in a primeval ocean which covered the whole earth, 

 and was of enormous depth. During the accumulation of 

 rock-precipitates certain large subterranean cavities filled with 

 air or vapour remained free from solid deposits. As the total 

 volume of water diminished, a considerable portion of the 



