M. Keilhau's Theory of Granite, and other Rocks. 399 



to the circumstance that many of the most important phenome- 

 na are altogether passed over ; and partly to this, that more of 

 those which have been touched on, have had rexiresentations 

 given of them Avhen they were but half examined, and which 

 often make tliem appear very different from what they really 

 are ; but we could not do otherwise than make ourselves ac- 

 countable for these defects, unless we were to drop our proper 

 part. It happens, unluckily, that a jireconceived theory ren- 

 ders an observer bhnd to the facts which do not harmonize with 

 his own conclusions; I will not make any remarks preju- 

 dicial to those observers who may not be willing to mark such 

 facts as do not coincide with their already received systems ; 

 all I mean is, that a preconceived idea often unfits us to attend 

 to those facts even when they present themselves, and incapa- 

 citates us from finding them when we have to seek for them. 

 In the description given, those facts only are mentioned which 

 might, with good reason, be expected in the statements of a 

 zealous supporter of the prevailing party. Those which have 

 been omitted are of such a nature as, I think, would render it 

 impossible to reconcile them to such statements. 



We shall now proceed to state the facts which, with the 

 greatest force, and in the most striking manner, seem to require 

 the rejection of the volcanic theory as altogether insufficient to 

 explain the existing phenomena. Then, if we should have the 

 good fortune to obtain a clearer view of matters, we shall, as 

 far as we can, seek for a more perfect delineation of the whole 

 subject. 



Let us first revert to the position of the strata in our terri- 

 tory. Here we are told, that extraordinary disturbances in this 

 respect have taken place. Highly inclined strata are not found 

 generally in the porphyry districts, where — for it must be thus 

 expressed in volcanic language — the molten masses must have 

 flowed out horizontally over the strata ; but still an elevation of 

 the beds is in general to be seen in every part of the granitic 

 districts, the masses of which have, on the whole, a more or less 

 vertical position at the side of the broken-up bed. Here, only half 

 of the truth is explained, for what relates to the facts, and what 

 is implied in the mode of expression, involve an explanation 

 totally false, which leads us to an equally false representation 



Dd2 



