Ch. XIV.] OF THE STRATIFIED ROCKS. 331 



latter, some might consider the line of disunion between the 

 ferruginous limestone and the incumbent bed to form the 

 boundary of the primary limestone : but much stress ought 

 not to be laid on this fact ; for it is more than probable that, 

 though it occurs at many points it may not hold good 

 throughout its whole extent. The beds of granite appear to 

 this distinguished geologist to afford positive proof that the 

 main mass of granite is more recent than the limestone. How 

 can we otherwise comprehend, says he, the intercalation of 

 granite between beds of dolomite, if the granite was not intro- 

 duced after the manner of veins ? According to the prevailing 

 theory it cannot well be otherwise; and he therefore has 

 concluded that these layers of granite are veins : but if this 

 be admitted as a justifiable conclusion, then all the layers of 

 granitic rocks found in the strata of gneiss, mica- slate, and 

 clay-slate, and parallel therewith, are also veins, though we 

 know by experience that these beds, in some cases, have no 

 connection with the adjacent granite. Under all these con- 

 siderations, it appears to us less objectionable to regard these 

 limestones, with their granitic beds, and the main mass of 

 granite, as members of the same primary formation, and con- 

 nected with the fossiliferous limestones by mechanical transi- 

 tions ; and, although the line of union may be at present 

 obscure, it may be hereafter detected by more minute ob- 

 servations, and nicer discrimination. 



It must not be omitted to remark, that secondary rocks 

 have been frequently found adjacent, and even in contact 

 with granite, without exhibiting an altered or metamorphic 

 appearance ; and yet at the same time, by the inclination of 

 their strata, indicating, according to the principles of the 

 Plutonic theory, that they have been elevated by the pro- 

 trusion of granite. Sedgwick and Murchison have recorded 

 many examples of this nature, in the Transactions of the 

 Geological Society, and have anticipated this objection, by 

 supposing that the granite has been forced through the strata 

 in a solid state. But in the north of Scotland, the phenomena 



