1 48 Hev. Mr WhewelFs Address to the Geological Society. 



of our members, some which may be considered as events of 

 primary importance in this part of our knowledge ; — steps 

 which may be described as a new foundation rather than a 

 mere extension of this portion of European geology ; — a sepa- 

 ration and arrangement of Transition rocks, which is likely to 

 become the type and classical model of that part of the geolo- 

 gical series, as Smith''s arrangement of the oolites became the 

 type of that portion of the strata. I speak of Professor Sedg- 

 wick''s views on the Cambrian rocks, which occupy the north- 

 west of Wales, and Mr Murchison''s on the Silurian formations 

 which cover the remainder of the principality and the adjacent 

 parts of England. Mr Murchison''s work, which cannot but 

 be one of first-rate value and interest^, will, I trust, be in our 

 hands in a few weeks ; and I should grieve to think that Pro- 

 fessor Sedgwick will be not only so unjust to his own reputa- 

 tion, but so regardless of the convenience and expectations of 

 geologists, as to withhold from the world much longer the 

 views which his sagacious and philosophical mind has extracted 

 from the accumulated labour of so many toilsome years, on a 

 subject abandoned to him mainly from its difficulty and com- 

 plexity. 



Turning, then, to the researches which have been laid before 

 us upon the earlier stratified rocks, I am first led to notice the 

 important memoir of the two gentlemen I have just mentioned, 

 upon the structure of North Devonshire. According to the 

 views of these gentlemen, founded upon an extended examina- 

 tion of the county, this portion of England forms a great 

 trough, having an east and west position, in which a series of- 

 culmiferous beds rest at their northern and southern extremi- 

 ties upon older rocks. The plants found in the culmiferous 

 beds are said to be all identical with species which are abun- 

 dant in the coal-fields of the central counties of England, and 

 of the South Welsh coal basin : and it was at first conceived 

 that these plants differed essentially from the scanty and im- 

 perfect remains of vegetables which are found in the older 

 rocks. More recently, however, the same fossil plants which 

 occur in the culm measures are said to have been detected in 

 the subjacent strata. Before this fact was known, the identity 

 of the fossils and the resemblance of mineralogical character 



