I 



Noles on Professor KeUhan's Paper on Granite, S^c. 367 



stance, that the outlines of the granitic masses present extremely irregu- 

 lar sinuosities, and observe also that these masses lie, &c It 



may be taken for granted, that the supporters of that theory, after having- 

 made their observations in about twenty places, and found nothing in the 

 least corresponding vyith their ideas, vrould give up this labour, and that 

 then, as I supposed in my description already given, they will remain satis- 

 fied with this brief conclusion, that the strata Aare 6een deraH(jrP(/ 



Three of my former pupils have faithfully assisted mc in this extensive 

 labour; and we traversed, two and two togctlier, the districts where the 

 massive formations have not taken the place of the stratified rocks. We 

 followed a strict method, almost as if we had been performing the duties 

 of a mining-engineer," &c. P. 401, 1. 23. It could not therefore be, un- 

 less by an accident difficult to admit, that these portions of a whole (and, 

 as well as the eruptionisls, we assume this original continuity) should pre- 

 sent such a conformable position of strata, if that had not existed before." 

 P. 402, 1. 1, the word " previous" should be left out. Vol. xxv. p. 82, I. 

 26. " The relations of the granite, and of the slate, are therefore not al- 

 ways such as we have previously described them ; it is certainly more 

 usual to find tliose rocks including each other at_ their junction, but this 

 relation is not exclusive, and it ought to be added, that we observe, at 

 least in some places, perfect passages from the granitic rocks to the sili- 

 ceous slates.'' P. S.*!, 1. 8. " Thus, in the case where thej' would adopt 

 for the crystalline slates, which touch the granite by means of a sharply 

 marked boundarj-, the mode of formation of which we have spoken, it 

 would not at all follow that this explanation can be applied to the case 

 v?here there exist perfect passages, so that it could not be said, for exam- 

 ple, in respect to the Solvsberg, that one portion of the granite existing 

 there is directly pyrogenetic, while the other, serving as a passage to the 

 slate, is rendered indirectly so by the influence of the first on the conti- 

 guous parts of the strata. If, however, any one, in order to support a 

 particular theory, should give such an explanation of the parts of the 

 Solvsberg, he ought, so as to g^ve some reason for these complete pas- 

 sages, to pretend that there exists here a special case, viz. that at the point 

 where the two granites come in contact, they resemble each other to such 

 an extent, that it is impossible to discover the slightest diflcrence between 

 them, and that the line of demarcation has become hardly perceptible by 

 reason of the fusion, if, indeed, it has not been completely effaced." 

 P. 84, 1. 81, for state read slate. P. 84, at the bottom. " It appears 

 that some of the supporters of this doctrine have endeavoured to ex- 

 plain the ramifications of the massive rock in the bounding strata, and 

 generally the relations of the boundaries and positions of these rocks 

 —relations which have of late been much more carefully examined — 

 by a.ssuming a simultaneous formation of the massive rocks and the 

 stratified rocks which arc often arranged together in so complicated a 

 manner. But after wliat has been said, this mode of escape will not; 

 •ufUcc; if it is maiataiucd that the granite of the transition territory 



