FOSSIL rOEESTS. 255 



Much the same change would be wrought by 

 the sea, the ever restless and never constant sea, 

 which is continually encroaching in some places 

 and retiring from others. Forest remains dis- 

 covered buried under existing sands by the sea- 

 shore prove that where the waves now roll in upon 

 the land, trees once flourished in magnificence and 

 beauty. Immersion for long years — centuries — 

 in water produces the curiously hard and perfect 

 material called bog timber. Immersion in sand 

 or earth causes the marvellous and wonderful 

 change called petrifaction, by which — though the 

 material is changed to stone, and sparkles with 

 stony brilliance — the original grain, and the spots 

 or other markings of the wood are preserved with 

 singular fidelity. By the wonderful and half- 

 mysterious process of Nature which geologists call 

 metamorphosis, this change is effected ; earths are 

 changed into rocks, rocks into other rocks, and 

 wood into stone. 



Many of these strangely interesting phenomena 

 have come to light by excursions into the body of 

 the earth ; but it will be sufficient to mention 

 two. A petrified Pine forest was discovered in 



