CHAP. VII.] 



MOUNT EGMONT. 



137 



sible by any agency whether by the pressure of a 

 superincumbent formation, or by igneous causes from 

 below, or by both agencies combined to convert that 

 mixture of trees and earthy or mineral substance into 

 the homogeneous substance which is spread out in 

 such regular stratifications, and which we call coal ? 

 I, for my part, cannot credit the possibility of such 

 a change. It is different with peat, which occupies 

 large tracts in the countries out of the tropics, very 

 often in horizontal and equal layers, and which we 

 see imbedding trees in an upright position. If arti- 

 ficially compressed it resembles coal far more than 

 does any lignitic substance that I have ever seen. 

 I have brought specimens of peat from the Chatham 

 Islands, taken from a layer not in actual formation, 

 but covered by a loamy earth several feet in thick- 

 ness. In these specimens, which it was evident were 

 formerly pure peat, I can observe a conchoidal frac- 

 ture and lustrous appearance greatly resembling 

 coal, whilst in other parts of the same specimen the 

 gradual transition from true peat is evident. I am 

 well aware that eminent geologists have contended 

 for the double origin of coal, and others will only 

 admit the simple one from wood; but they will, 

 probably, come to a different conclusion if they turn 

 their attention more to present processes, and divest 

 their minds of preconceived ideas regarding a differ- 

 ence of phenomena in former days. 



One of the Sugarloaf Islands also consists of 

 aqueous deposits, namely, yellow and soft sandstone. 



