132 ON THE REVOLUTIONS OF 



Exaggerations with respect to certain Operations in Mines. 



The antiquity of certain mining operations has been greatly exag- 

 gerated. A modern author asserts, that the mines of the island of 

 Elba, judging from the heaps of rubbish excavated from them, must 

 have been worked for more than forty thousand years ; but another 

 author, who has also examined these rubbish heaps with care, reduces 

 this period to rather more than five thousand years *, and then, in sup- 

 posing that the ancients only excavated annually but a quarter of the 

 quantity now extracted. But why should we believe that the Romans, 

 who consumed so much iron in their military arrangements, should 

 draw so little from these mines ? Besides, if these mines had been 

 worked for four thousand years only, how should iron have been known 

 in days of such remote antiquity ? 



General Conclusion concerni7ig the Epoch of the last Revolution. 



I concur, then, with the opinion of MM. Deluc and Dolomieu, that 

 if there be anything determined in geology, it is, that the surface of 

 our globe has been subjected to a vast and sudden revolution, not 

 further back than from five to six thousand years : that this revolution 

 has buried and caused to disappear the countries formerly inhabited by- 

 man, and the species of animals now most known ; that contrariwise 

 it has left the bottom of the former sea dry, and has formed on it the 

 countries now inhabited : that since the revolution, those few indivi- 

 duals whom it spared have been spread and propagated over the lands 

 newly left dry, and consequently it is only since this epoch that our 

 societies have assumed a progressive march, have formed establish- 

 ments, raised monuments, collected natural facts, and combined scien- 

 tific systems. 



But the countries now inhabited, and which the last revolution left 

 dry, had been before inhabited, if not by mankind, at least by land 

 animals ; consequently one preceding revolution, at least, had over- 

 whelmed them with water ; and, if we may judge by the different or- 

 ders of animals whose remains we find therein, they had, perhaps, un- 

 dergone two or three irruptions of the sea. 



Ideas of Researches to be still further made in Geology. 

 These are the alternatives which now appear to me to form the most 

 important geologic problem which requires solving, or rather, properly 

 defining, or accurately limiting; for, to solve it entirely, it would be 



* See M. de Fortiad'Urban's History of China before the Deluge of Ogyges, p. 33, 



