264 ON THE FORMATION OF ROCKS. (June, 



of a total change in the general laws of nature, because 

 the agents necessary to the retaining of matter in one 

 state, must be disposed of before that matter can acquire 

 a different form or nature. 



It is, perhaps, an historical fact, that all geologists 

 who have formed their systems on the examination of 

 the northern parts of the continent of Europe, where 

 there are no existing volcanoes, are neptunists; and those 

 who have examined Italy, or other volcanic countries, 

 previous to the formation of their systems,. are more or 

 less volcanists, which tends to prove, that opinions 'are 

 the result of our knowledge, and our knowledge the 

 consequence of the difierent situations which chance or 

 choice has thrown us into: we ought, therefore, not to 

 be astonished, much less irritated, at the difference of 

 opinions, but consider them as the natural effect or conse- 

 quence of our locality or opportunities. 



Suppose the earth was a body of moderate size, that 

 we could cut up and dissect as we do animals, vegeta- 

 bles, or other objects of natural history, it is probable that 

 the first part which would attract our attention would be 

 the volcanoes, in action, with the mountains formed by 

 the ejected matter; we should probably first examine the 

 nature of this ejected matter, to ascertain what proportion 

 of tlie surface of the globe, or ball, was covered with 

 similar matter: we should, of course, find out the extinct 

 volcanoes, and though the fire had ceased to act, the si- 

 milarity and relative position of the matter would induce 

 us to conclude that they were produced in the same man- 

 ner, as well as the small detached remains of similar sub- 

 stances, which we would find scattered over the whole 

 surface. 



