406 ON THEORIES OF THE EARTH. 



In arguing against subsidences, we trace, equally, 

 the spirit of hypothesis and antagonism, with a want 

 both of geological knowledge and sound reasoning. Of 

 some structure of discontinuity, if not strictly ca- 

 vernous, there is evidence in the linear directions of 

 volcanoes ; as coal, and more, are proofs of subsi- 

 dences. Though gneiss, and some other primary 

 strata, are in their present condition from heat, this 

 mode of consolidation cannot be admitted for all strata. 

 The theory of trap is untrue, because injudiciously 

 rigid : while the anxiety of opposition has introduced 

 inextricable confusion into this part of the system; 

 under which, also, he has, by disclaiming demonstrated 

 truths, forfeited one of his strongest supports, while 

 maintaining a perpetual hostility against Dolomieu 

 and Faujas de St. Fond, on the very facts by which he 

 might have profited, but did not understand. Knowing 

 the igneous rocks most imperfectly, he denies the ex- 

 istence of scoriform traps ; while having recourse to a 

 most unhappy expedient for explaining the ainygda- 

 loidal nodules. Perpetually indeed misapplying a fa- 

 vourite principle, even though admitting water to a 

 large share in his operations, it is called on where nei- 

 ther needful to the theory nor reconcileable to the 

 facts. Such is the unnecessary fusion of carbonat of 

 lime, with the igneous origin of quartz, chalcedony, 

 and silicified wood ; while the theory of flints is pecu- 

 liarly infelicitous and unintelligible, as is that of the 

 septaria. But the whole theory of igneous secretion 

 is without excuse ; as it compels us to deny that this 

 writer was the chemist he has been called. The theory 

 of coal equals the very worst of the schemes of Wer- 

 ner ; while it indicates that narrow spirit of hypothesis 

 which misapplies a sound principle as often as the re- 

 verse ; proving, that reasoning was, in any case, a very 



