Ch. III.] COMPARED WITH THOSE OF CORNWALL. 33 



the primary slates in this part of Saxony, and the manner in 

 which they are connected with the granitic rocks, will be con- 

 sidered in another Chapter. 



In the most extensive primary districts of Europe, how- 

 ever, the granite is not disposed in such rounded and insulated 

 masses, but is more or less elongated, so that, when viewed 

 on the large scale, it has the appearance of immense beds, 

 interstratified with the schistose rocks ; under these circum- 

 stances, it is now generally regarded, not as true granite, but 

 as granitic varieties of the strata with which they are asso- 

 ciated. This point will be discussed hereafter ; we shall only 

 now observe, that the most eminent geologists have differed 

 on this subject ; some contending, that these granitic beds, 

 having the same physical and mineral characters as granite, 

 are perfect and veritable granite, whilst others have main- 

 tained the view just given ; thus, the immense granitic masses 

 of Sweden and Norway have been by some pronounced to be 

 true granite, whilst by others they have been denominated 

 granitic gneiss, because smaller layers of the same rock are 

 interstratified with, or completely enveloped in, the gneiss. 



For similar reasons, most geologists assert that the granitic 

 rocks of the Hartz mountains are members of the stratified 

 rocks, or intruded masses of a more recent origin, because 

 they, in some cases, alternate together, and also with crys- 

 talline schists, which gradually pass into the greywacke 

 formation : we will, therefore, select this example for a de- 

 scription of this kind of granite, waiving all theoretical con- 

 siderations for the present. 



Several of the principal summits of the Hartz are crowned 

 with granite, which exhibits the ordinary appearance of this 

 rock, being traversed by three systems of fissures, one parallel 

 to the horizon, and the others perpendicular, so as to divide 

 the mass into cuboidal blocks, the solid angles of which have 

 been rounded by the action of atmospheric agents. The 

 granite is composed of the common ingredients, felspar, 

 quartz, and mica, sometimes the felspar, and at others the 



D 



