48 REPORT — 1842. 



structure in the ashes of anthracitic coal received from Sir H. De la Beche. Mr. Phil- 

 lips considered this evidence, as far as he had collected it, rather in favour of the 

 view that particular beds of coal were in a great measure formed by plants growing 

 on the spot, and not by drifting : the evidence of such drifting existed in many cases, 

 and formerly predominated ; but he had met with many phaenomena, and this amongst 

 them, which tended to diminish the force and generality of his former conclusions. 

 He was, however, still engaged in the prosecution of this inquiry. 



On the Origin of Coal. By W. C. Williamson, F.G.S. 



In this communication the author had collected all the principal facts and phe- 

 nomena bearing upon the origin and formation of coal, with the view of proving it 

 to have originated in the drifting of vegetable matter into the sea, and not by the 

 accumulated growth on the same spot now occupied by the coal- The strata sepa- 

 rating the coal seams were described as consisting of a great variety of rocks, from 

 the coarse deposits and water- worn pebbles of the lower grits to the fine-grained 

 shales and limestones of Ardwick ; they were acknowledged by all to have been se- 

 dimentary in their origin, containing the remains of aquatic shells and animals. In 

 many of these strata, as at Colebrook Dale, the scales and other remains of Mega- 

 lichthys were found abundantly associated with Orthoceratites, Goniatites, Naticae, 

 and a variety of other shells whose marine character had never been doubted ; in the 

 coal-measures of Yorkshire Pectenpapgraccus, several Goniatites, several species of a 

 genus allied to Modiola, Lingular, Crustaceans allied to the recent marine genera 

 Cyamus and Cymothoa, were found, with remains of Megalichthys, Palaeoniscus, Pla- 

 tysomus, and other fish. The abundance of shells commonly considered Unionidse, 

 did not, in the author's opinion, militate against the marine origin of the former, as 

 Dr. Fleming mentions having seen the dead shells of Unios, with their valves still 

 united by the ligament, in abundance at Mount Vernon on the Potomac, and at 

 Montmorenci on the St. Lawrence, both placed where the tide flows ; and Mr. Wil- 

 liamson inferred that if the current could carry them so far, some might also reach 

 the estuaries of those rivers, and become mixed with marine remains. He then de- 

 scribed the conditions under which vegetable remains, such as Halonia regularis, Ca\a- 

 mites, Sigillariee, Stigmariae,Lepidodendra, and the fruit of Trigonocarpon, were found 

 imbedded in the coarse grits and solid sandstones of the Halliwell quarries and Peel. 

 These remains had all lost their stalks or foliaceous appendages, and were so inti- 

 mately a part of the sandstone, that if one was drifted the other must have been 

 transported in the same way. In the beds of shale unconnected with coal, large ac- 

 cumulations of plants were often found occasionally mixed with Unionidse and mi- 

 nute Entomostraca, presenting the appearance of having been thrown down together, 

 after floating about in the water ; the author considered these layers only differed in 

 amount from the coal-seams ; in one case a large and dense mass of vegetable 

 matter had formed the material of a bed of coal, in the other the fewness of the 

 plants and their intermixing with mud, now forming the shale, had limited the pro- 

 cess to the conversion of each plant into a thin layer of carbonaceous matter. The 

 author attributed the scarcity of fish-remains in the coal itself to the action by the 

 same chemical process which had converted the accumulated vegetables into coal ; 

 the occurrence of scales of Megalichthys in the cannel coal of Dixon Green and 

 Wigan, he attributed to some peculiarity in its origin or composition more favour- 

 able to their preservation. The absence of the usual coal measure plants in the fire- 

 clay underlying the coal proved, in the author's opinion, a want of any connexion 

 between the two ; and he was disposed to adopt the view of those who regarded the 

 Stigmaria of the fire-clay as a marine, or at least aquatic plant, growing in 

 those estuaries in which the drifted vegetable remains of the higher country would 

 be sunk, and form a deposit of coal over them ; but he observed that, although 

 coal rarely occurred without this subjacent layer of stigmaria, yet the latter was fre- 

 quently found independent of coal. The author proceeded to state what he 

 considered another proof of the drift origin of coal and associated beds in the dis- 

 jointed and fragmentary condition of the fossil ferns and other plants, and the almost 

 universal absence of their rhizomas and roots, which he stated he could only account 

 for by supposing the remains had been long exposed to the action of water in rapids 



