M. Keilhau's Theory of Granite and other Rocks. 391 



some of these side offsets, issuing out in this manner, are so 

 large as in some places to exhibit the appearance of sometimes 

 an overlying and sometimes an underlying position of the mas- 

 sive formation in respect to the transition strata; but nevertheless 

 the relative situation upon the whole, as we have already remark- 

 ed, is to be regarded as juxtaposition, a condition which, taken 

 in connection with the ramifications springing from the chief 

 masses, naturally leads to the supposition of a previous liquid 

 condition of these rocks, in which state they were pressed up- 

 wards from the interior. Yet, with this view of the subject, 

 one cannot possibly avoid being struck with a high degree of 

 astonishment, in considering the magnitude of these masses. In 

 the whole of the wide space that they occupy, there is generally 

 no trace of divisions or of such separate portions as could indi- 

 cate that several ejections had taken place. Every one of these 

 enormous masses must be considered as the result of one single 

 eruption, or, so to speak, as one gush from the furnace, one 

 casting in a foundry. In taking this view, it must also appear 

 surprising that these granitic masses, which must thus be con- 

 sidered as thrown up through canals of several miles in breadth, 

 do not nevertheless form particularly high mountains. Some 

 of their highest summits may be 2000 or 3000 feet above the 

 level of the sea ; but the unevenness arising from these is very 

 inconsiderable ; for if one were placed so that with one glance 

 he could look over the whole surface of these masses, — such, for 

 instance, as have an extent of 200 square English miles, — it 

 would appear to him that this surface was tolerably level, that 

 is to gay uneven only on the .small scale. Such a form cannot be 

 explained but on the supposition, that this open gap was filled 

 just to the edges, that by a singular chance there was no more 

 of the molten ma«s forthcoming, and that thus there was not 

 enough to furnish a rising on the top. 



But these circumstances will have but little weight with him^ 

 who is inclined to consider the masses in question as the pro- 

 ducts of the action of fire ; for, in addition to them, he will 

 find abundance of phenomena which are generally received as 

 proofs of the Plutonian origin of such rocks. He will find many 

 highly inclined, nay perpendicular strata, at most of the places 

 'on the granite boundaries ; he will observe dark-coloured com- 



