OF THE EARTH. 503 



gled in our primary strata, and this therefore is the 

 very granite which elevated the Earth which I have 

 here called the second ; while, if the quartz of the 

 other fragments be derived from granite, as is probable, 

 it will be evidence of an anterior one which elevated 

 that one here marked as the first ; the evidence, as I 

 formerly explained, being incapable of reaching fur- 

 ther. It demands a second production of granite, or 

 of the older porphyries, which are of the same general 

 a?ra, to elevate the primary strata ; and a third to ef- 

 fect the elevation of the lowest secondary ones. Now, 

 of these, we have the most abundant evidence in those 

 granites, of which the veins of one kind traverse the 

 mass of another ; and thus I have provided for those 

 conditions here called the third and the fourth. Again, 

 it requires a fourth production of an unstratified rock 

 to produce that change which attended the depression 

 of the coal strata. Now there have been granites found, 

 where a vein of a third granite traversed a vein of a 

 second and different one which had previously traversed 

 the mass of a first ; but if this should be doubted, 

 there are two antient porphyries which successively tra- 

 verse a mass of granite, the last of these being, of 

 course, the third production. 



Thus is every necessary cause of revolution demon- 

 strated as to the fifth earth of this arrangement ; while, 

 from this point, I can no longer certainly trace any 

 further mutual interferences of granite or antient por- 

 phyry. But that is of no moment ; since there arc 

 abundant resources in the production of the trap rocks, 

 of which two formations, or perhaps more, are demon- 

 strated, adequate to even more than is required, while 

 they account for the sixth and last condition of the 

 Earth. Beyond this, the demonstrations are admitted 

 by every one, in the volcanic rocks of higher antiquity, 

 and in the disputed traps ; and, lastly, in those of ex- 



