Bernards, on Professor Kielhau's Theory of Granite. 371 



found that the essential distinction in the processes consists entirely in 

 the time required," &c. In reference to the remark on alum-slate, at 

 p. 271, 1. 8, the author adds the following note : — " I would remark that 

 there are two indications of the force which seems to react on the meta- 

 morphoses, and which maybe said to impede them; Ist, That we do 

 not find the ordinary changes near the granite when the primitive rock 

 is very near at hand ; and, 2d, That they are likewise not found at the 

 contact of the eurite-porphyry — (because ?) in both cases, it is the bitumi- 

 nous ampelite which touches the abnormal rocks." P. 271, 1. 13, " That 

 the porphyries, in general, do not produce those contact phenomena which 

 are so distinctly displaj-ed near the limits of the granite and the primitive 

 rock, is a fact which deserves to be again mentioned. Masses in a state 

 of fusion, -whether,' when they were solidified, they became porpyhry or 

 granite, ought to have produced nearly the same actions." 



Itemarks on Professor KeilhaiCs Theory of Granite, S^c. By 

 Baron Jacob Berzelius.* 



Keilhau, who has enriched geology with so many beautiful 

 and important observations upon the subject of the relations 

 of the junctions of the oldest rocks, and the various older and 

 vounger rocks reposing on them, and produced at different 

 later periods, has, from the collected experience derived from 

 these relations, which are often of the most singular descrip- 

 tion, and of a kind to defy our explanations, endeavoured to 

 form a theory regarding their origin, which he made public 

 in the 1st vol. of the New Magazine of Natural History, un- 

 der the title of " The Theory of Granite and the other Mas- 

 sive Rocks," &c.t 



The Norwegian Geological School of Esmarck, its much es- 

 teemed founder, who directly derived his knowledge from the 

 chair of Werner at Freyberg, originally held the opinion of 

 Werner as to the formation of rocks, partly by crystallization, 

 and partly by precipitation from water. In this doctrine 

 Keilhau was educated, but his own observations have gradu- 



* Translated from his " Arsbcriittelse om Frarastegcn i Fysik och 

 Komi," for 1837. 



t Sec this Journal, vols. X-xiv. and xxv., and tlic i)resent number, p. 350. 



