GEOLOGY. 157 



Since we have abandoned systems to confine 

 ourselves to the observation of facts, and to com- 

 pare these observations ; since we have renounced 

 the attempts to guess the origin of things, to ascer- 

 tain their actual state; geology, which formerly 

 belonged to the domain of imagination, has followed 

 the course of the positive sciences. This regular 

 method has not only extended our knowledge of the 

 construction of the earth, but has even produced 

 results useful to the arts. We are far however 

 from knowing the different countries of the globe 

 as we know Europe, and the facts necessary for 

 fixing our ideas can only be collected by travellers, 

 who are well informed on, and devoted to, this kind 

 of study. But it is very easy for those who visit 

 distant countries, especially beyond the tropics, to 

 procure us important notices, and to send us pro- 

 ductions, the examination of which alone can en- 

 lighten and furnish us with ideas on the nature of 

 the soil in different countries, and consequently the 

 general disposition of the minerals which cover the 

 surface of the globe. On all coasts, in all the 

 islands, where a vessel harbours, those who go on 

 shore can without much difficulty procure objects, 

 which, not possessing any value in themselves, may 

 become instructive and interesting from the notes 

 by which they are accompanied. They first collect, 

 on the borders of rocky torrents, fragments which 

 indicate the nature of the rocks over which they 

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