SECOND EDITION. 



THIS Edition, so speedily called for, contains few new 

 facts or discoveries, but it embodies three additional 

 chapters one 011 Metamorphism, or that internal 

 change which every rock in the earth's crust is in- 

 cessantly undergoing; another on Veins, their nature 

 and origin ; and a third on What we owe to our Coal- 

 fields. Besides these chapters, which seem necessary 

 in a compendium of General Geology, a number of 

 emendations have been made throughout the work 

 the author's desire being to render it still more ac- 

 ceptable to that extensive and ever-increasing section 

 of readers for whom it is specially intended. 



October 1866. 



