298 Communications respecting Bocks of Scandinavia. 



On the BIctamorphoscs of Eocks. 



You call Noi'way the classic land for metamorphoses of 

 rocks. It is so, inasmuch as this theory in its present form 

 was first put forth there : but any other mountainous region 

 offers just as good opportunity for evolving these views. In 

 the Alps, for instance, does not every step lead to changes 

 which the rocks have undergone I '* The same stamp,'' says 

 our great master, " is impressed upon nature from the Alps 

 as far as the North Pole. Her laws are extended universally 

 over the surface of the earth.'' 



The advantage which Norway affords for the study of the 

 relations of rocks, consists in the severity of its climate per- 

 mitting the growth of no luxuriant vegetation, which is so 

 inimical to geognosy. To this is added the circumstance, 

 that no high hills have to be climbed in order to trace the 

 geognostical relations, and in fine, that the capital of the 

 country, Christiania, lies exactly in the middle of that rich 

 region. 



Professor Keilhau, of Christiania, treats of the geology of 

 his country according to the metamorphic theory.* It would 

 almost appear to me as if he went too far in his complete re- 

 jection of chemistry and physics. For by this he plainly 

 damages his own cause, first, by rejecting the aid of all 

 those who steadily adhere to the positive (principle) in 

 science ; and also, by depriving himself of many fine explana- 

 tions ; for only by the aid of chemistry it appears sheAvn 

 that alum-slate, which plays such a considerable part in 

 the geology of Norway, furnishes the material of gneiss, 

 since it has the same chemical composition ; and in Natural 

 Philosophy alone can we hope to find an explanation for the 

 new arrangement of molecules in the crystalline limestone of 

 Gjellenbak, which at the same time contains petrifactions. 



It is indeed a peculiar phenomenon, that everywhere in 

 which the im altered transition rocks come in contact with 

 the gneiss, the former consists of alum-slate, which, in 



* Profcssoi" Keilliau's celebrated Memoirs on Metamorphic Rocks were first 

 published in this country in the 23d and 25th volumes of the Edinburgh New 

 Philosophical Journal, and under the immediate superintendence of the cele- 

 brated Author. 



