INTRODUCTORY REMARKS. 



In tracing the features, and studying the rocks and compounds of 

 the earth's surface, no problem has more frequently occupied the mind 

 of geologists than the formation of coal. Where does this black sub- 

 stance come from, hard as stone, and nevertheless inflamable as wood; 

 half bitumen, half charcoal, encased between beds of shale and rock, 

 which, by their fossil remains, their fishes, shells, or plants, attest the 

 highest antiquity ? Has coal been originated in the bowels of the 

 earth by some volcanic agency, and deposited in a fluid state, like the 

 lavas or the primitive rocks of many mountains ? No ! for it is strat- 

 ified, laminated, extended in horizontal beds, covering very large sur- 

 faces with a nearly constant thickness. Moreover, the shales in which 

 it is ordinarily incased bear evident proofs that they have been slowly 

 deposited in a quiet water basin, and that subterranean fire has had no 

 action upon them, except perhaps as a hardening agency. Or, perhaps, 

 has coal been made of the remains of extensive forests, overthrown, 

 transported, and deposited again in valleys and hollows, by an uni- 

 versal flood. But, by such a cataclysm, those remains could not have 

 been distributed in an harmonious manner, in extensive beds of equal 

 thickness, and especially in such purity that they scarcely contain any 

 particle of mud, sand, or any substance that does not belong to the 

 chemical compounds of the wood. For the same reason, also, the beds 

 of coal cannot be the result of heaps of drift-wood along the banks of 

 the large rivers, or on the shores of the sea. It is then necessary to 

 admit, with most of the best living geologists, that the coal beds have 

 been formed nearly in the same manner as the peat-bogs of our own 

 time, and that the coal itself is nothing else but decomposed and har- 

 dened woody matter, remains of immense and successive forests, grown, 

 decayed, heaped up, and then entombed on the spot, in their gigantic 

 shrouds of black slate, of black, white, and grey limestones, or of yel- 

 low sandstone. 



But such an explanation is too general, too indefinite, to be easily un- 

 derstood, and especially to give a satisfactory account of the various 



