472 ON THE NEWEST FLOETZ-TRA? 



vision of its parts in the menstruum from which it 

 was deposited, only so far as the line which may 

 be imagined between mechanical suspension and 

 9 chemical solution ; and such a precipitate, it can 



easily be conceived, might unite an earthy aspect 

 with a considerable degree of crystalline regulari- 

 ty. From this peculiar state of the felspar on the 

 amygdaloidal rock, I have already observed, that 

 through the superincumbent claystone, basalt and 

 clinkstone, there is a gradual acquisition of lustre, 

 transparency and hardness, passing through com- 

 mon, and ending in glass}' felspar, or a variety of 

 adularia, which is undoubtedly a deposition from 

 perfect chemical solution. I had occasion to make 

 what I conceive to be an important remark in the 

 present state of the science, namely, that much 

 more than one-half of the extensive tract of coun- 

 try which I explored, was covered with that as- 

 semblage of rocks of the flcetz-trap, — a fact which 

 considerably weakens, if not entirely destroys, an 

 objection of the Huttonians against the universa- 

 lity of this formation, from its supposed non-oc- 

 currence in this country. It is now not only a 

 fact, that this formation is extensively distributed 

 in this vicinity ; but also that a series exists here 

 perfectly analogous to those at the Scheibenberg, 

 upon which the Wernerian theory of aqueous de- 

 position was particularly founded. 



