and Writings of Baron Leopold von Buck, 215 



by a perpendicular shock ; and hence he termed all islands 

 thus formed Islands of Elevation, and their central cavities 

 Craters of Elevation^ which last he was induced to distinguish 

 carefully, and according to their nature, from Craters of Erup- 

 tion, He had also remarked that many of the volcanos dis- 

 tributed over continents, so far as we are intimately acquainted 

 with them, are, like these islands, surrounded by a similar ex- 

 ternal ring ; and hence the relation of craters of elevation to 

 craters of eruption has come to be considered as a natural law 

 frequently exhibited in districts of volcanic origin. 



Ingenious and acute as this view is, and much as it contri- 

 butes to the simplification of our ideas on volcanic subjects, it 

 was by no means at once received generally by geologists after 

 its announcement. The English geologists especially, as Dau- 

 beny, Scrope, and Lyell, did not assent to it ; and in France 

 likewise it has been made the subject of a very obstinately 

 conducted controversy. The opponents of Buch's opinions 

 have urged, as their chief argument, that all volcanos partly 

 produced under our observation, or, if extinct, provided with 

 distinctly preserved craters of eruption, which have been 

 formed by the gradual heaping up from the centre of the sub- 

 stances forming their acclivities, are constructed in a manner 

 precisely similar to islands of elevation. 



However this difference of opinion may be decided, the vol- 

 canic origin of the islands distributed over the great ocean re- 

 mains at all events untouched ; and Buch has annexed a very 

 complete general view of the distribution of volcanic action 

 over the whole surface of the globe. The conclusions obtained 

 from this delineation are very remarkable ; for it results that 

 the volcanos on the surface of the earth lie collected chiefly in 

 certain lines, which very frequently have a relation to one 

 another. These lines he proposed to account for in a very 

 natural manner, by great fissures through which the subter- 

 ranean forces formed a path for themselves, and it is undoubt- 

 edly very remarkable that these lines not only very frequently 

 correspond generally with the outline of the great continental 

 masses, but also that, in detail, they run parallel to the course 

 of higher mountain-chains, composed of older elevated rocks, 

 at whose base they break forth. 



