18ia.3 ON THE PORMATION OP ROCKS. 335 



seldom alternates with it. In this way confusion of 

 names takes place. A Neptunian geologist travels over 

 a country, where the rocks of the newest flooetz trap 

 ©ccur: he finds trap, greenstone, and greenstone 

 ti'aps, porphyries, clinkstone, basalt, &c. &c. A Vol- 

 canist travels over the same ground, and he describe^ 

 it as consisting of different species of Lava. 



Werner being the first that made any classificatiou 

 of rocks, his disciples of course were the first who 

 made any geological observations 5 and as they seemed 

 all much interested in putting this class of rocks into 

 the Neptunian origin, they passed slightly over them; 

 and described them by Neptunian names. This may 

 perhaps be one reason why they are not so generally 

 known as other rocks, and why they are to be founcl 

 in greater abundance on the surface of the earth thaa 

 was generally supposed. When, positive and liberal 

 examinatio]! takes the place of that party and system* 

 atic spirit, which seems to have no other object in vlcvV 

 than the support of a theory purely conjectural, de* 

 pending on the fancy of the author, and changed and 

 overturned by every new inventor of systems, it ie 

 then that the science of geology will make rapid pro- 

 gress, and be ranked according to its r^al utility^ 



This class of rocks is scattered over the surface of 

 (he globe. I found them in the Crimea i along the 

 south side of the Bohemian mountains ; an both sides 

 of the Saxon mountains, but more common on the 

 south side; near the Rhine at Holicnweiler and Old 

 Brisack ; scattered over the country of Tliiiringia and 

 Hessecastle ; occupying tiie tops of the Jiiib tiirough 



