342 On the Bocks said to be older than the 



organic remains have yet been discovered, we may afl&rm that the 

 gneiss of Kinnekulle in Sweden before alluded to, or of the 

 falls of Montmorenci, and many of the unstratlfied or Plutonic 

 rocks of the Adirondack Mountains, vi^est of Lake Champlain, 

 are truly primary. We may also extend the same appellation, 

 without much liability of error, to all the crystalline rocks 

 found for a considerable space on every side of the points 

 where the lowest strata charged with fossils are incumbent 

 upon the non-fossiliferous formations. But the farther we go 

 from such points of departure, the more unsafe does our gene- 

 ralization become ; and the American geologists have already 

 found reason to retract their first conclusion, that the gneissose, 

 micaceous and talcose schists, of the Taconic range (see above, 

 p. 245, vol. i.), are referable to a primary series. 



The posteriority of age of many masses of granite and other 

 Plutonic rocks, is more easily proved than the modern origin 

 of the stratified hypogene formations, because the former pro- 

 duce alterations of moderate extent, at the point of contact, or 

 send veins into the newer fossiliferous strata. But where these 

 strata have been altered on a great scale in texture, by heat 

 and other subterranean causes, the evidence of transmutation 

 is difficult to detect, in proportion to the intensity of the meta- 

 morphic action. The study of the Alps and Apennines has 

 shewn, that it is characteristic of such action to annihilate all 

 signs of the date of its development, by the obliteration through- 

 out entire mountain masses of all traces of organic structure. 

 We are therefore entitled, on every principle of sound reason- 

 ing, to suspect, that for one case where we can positively esta- 

 blish the secondary origin of any set of crystalline strata, there 

 are many others where the proofs of their modern origin have 

 been destroyed. 



A geologist, whose observations had been confined to Swit- 

 zerland, might imagine that the coal measures were the most 

 ancient of the fossiliferous series. When he extended his in- 

 vestigations to Scotland, he might modify his views so far as 

 to suppose that the old red sandstone marked the beginning of 

 the rocks charged with organic remains. He might, indeed, 

 after a search of many years, admit that here and there some 

 few and faint traces of fossils had been found, in still older 



