«S£ On the Basaltes of Saxony. 



he declares that he will comprehend among their produc- 

 tions those substances only luhich have been completely fused 

 and altered by subterranean fires, and which a volcanic crup* 

 tion has afterwards conveyed to those places where they are 

 found at present >, that is to say, substances similar to those 

 thrown up in our days by iEtna and Vesuvius. In regard 

 to the testimonies which might be deduced from the real or 

 supposed existence of extinguished volcanoes, he rejects 

 them, because their existence, he says, is a matter of dis- 

 pute. C. Daubuisson, therefore, will not easily be con- 

 vinced by the experiments of Sir James Hall, which prove 

 that gradual cooling may restore a stony appearance to fused 

 and vitrified rocks : consequently he will be under no em- 

 barrassment from that lithoid lava, which, according to 

 Dolomieu, cannot be distinguished, but by its position, from 

 analogous stones which have not been subjected to the ac- 

 tion of fire : to explain the latter, therefore, he will have no 

 Meed of recurring to another mode of fusion, another degree 

 of heat, than that which has given its form to common lava. 

 He rejects all these suppositions, as so many hypotheses, 

 invented without any foundation, to explain facts which are 

 themselves hypotheses. It may be readily perceived that 

 to lay down the question in this manner is to determine it 

 beforehand, since the whole is then reduced to basaltes, 

 and that it would be sufficient to prove that this basaltes 

 has none of the characters which distinguish lava, whose 

 origin is beyond dispute. It will, however, be found that 

 the author does not always adhere to this negative kind of 

 proof. 



In the second chapter, C. Daubuisson proceeds to a ge- 

 neral and particular description of the basaltic chain of 

 Saxony. This part of his labour deserves great praise, on 

 account of the method which prevails in it, and which it is 

 much to be wished were to be found in the works of other 

 geologists. 



The chain which he describes, remarkable for the great 

 number of veins it contains, is called the Erz^Gcbirgc, or 

 metalliferous chain. It separates the electorate of Saxony 

 from Bohemia, and runs north-east for the extent of about 

 130 miles. The maximum of its elevation is about a thou- 

 sand yards above the plains of Saxony, or from eleven 

 to twelve hundred above the level of the sea. Its nucleus 

 is granite ; but this rock is almost entirely covered with 

 strata of gneiss, micaceous and argillaceous schist. There 

 are found in it also serpentine quarts?, calcareous strata, 

 coalsj and clay. The whole of the eastern part is covered 

 4 towards 



