8 STEVENSON— FORMATION OF COAL BEDS. [April 21. 



sented with some pieces of coal that were got near the top of Whernside 

 and the other mountains, that seemed more like dry clods of peat moss than 

 coal, though distinguishable enough to belong to the latter class. The 

 principal difference in their composition is that coals abound with the vitri- 

 olic, and peat moss with the vegetable acid. The vitriolic acid is diffused 

 through every subterranean stratum ; hence if a quantity of earth should be 

 superinduced above a stratum of peatmoss, the vitriolic acid that would 

 ouse through, must in time change its nature and turn it into coal : the 

 deeper it lay below the surface of the ground, the more it would be im- 

 pregnated with this fossil acid, and consequently be the more inflammable. 

 If a stratum should lie near the top of a mountain, there is the less chance 

 that it should be well fed. 



Williams'' was an unedticated man btit an admirable observer, 

 who stnnmarized in his vohtmes the results of studies in much of 

 Great Britam. He was a firm believer in the vegetable origin of 

 coal and equally in the wide extent of the Noachic deluge. Think- 

 ing that he could identify in some coals the wood of modern species, 

 he suggested that, prior to the deluge, only a small part of the globe 

 was inhabited and that most of it was covered with tall trees. Those 

 trees, swept off by the deluge, were carried by currents and deposited 

 in limited areas. But this hypothesis does not satisfy all the condi- 

 tions, for he had found coals which closely resembled peat. He 

 says, " I will here beg leave to propose another probable source of 

 coal. I believe I may call it a real one, and that is the antediluvian 

 peat bog," and this is followed by a discussion of peat bogs, their 

 structure and growth. 



Williams argues strenuously against any hypothesis that the ma- 

 terials of the strata were formed by settling of particles from a 

 heterogeneous mass in accordance with gravity, for the order of the 

 beds is evidence to the contrary. At the same time, he finds in 

 the structure of coal beds evidence that most of the beds were 

 formed of transported timber. " I am of opinion that the ante- 

 diluvian timber floated upon the chaos or waters of the deluge, . . . 

 and that during the height of the deluge and the time in which the 

 greatest part of the strata were forming, the timber was preparing 

 and fitted for being deposited in strata of coal." 



° J. Williams, "The Natural History of the Mineral Kingdom," Edin- 

 burgh, 2d ed., 1810, Vol. I, pp. 510, 522-525. The first edition was in 1789. 



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