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that several millions of piastres have been 

 rashly expended in South America, from a 

 complete ignorance of the nature of the forma- 

 tions, and the position of the rocks, in direct- 

 ing* the labors of research. It is not solely the- 

 precious metals which should now fix the at- 

 tention of the new associations of mines ; the 

 multiplication of steam-engines, renders it in- 

 dispensable, wherever wood is not abundant, or 

 of easy transport, to seek at the same time to 

 discover coal and lignites. In this point of 

 view, the precise knowledge of red sandstone, 

 or coal-sandstone, quadersandstein and molas- 

 sus (tertiary formation of lignites), often cover- 

 ed with basalt and dolerite, is of great practical 

 importance. It would be difficult for a Euro- 

 pean miner, recently disembarked, to judge of 

 a country with a new aspect, and when the 

 same formations cover an immense space. I 

 flatter myself that the work I now publish, as 

 well as my Political Essay on New Spain, and 

 my work on the Position of rocks in the two he- 

 mispheres, will contribute to diminish those ob- 

 stacles. They may be said to contain the first 

 geognostic knowledge of places of which the 

 subterraneous wealth attracts the attention of 

 commercial nations, and they will serve to class 

 the more precise notions which ulterior re- 

 searches will add to my labors. 



The republic of Colombia in its present li- 



