120 Theory of the Oiigin of Coal. 



if we insist exclusively upon the submergence of forests or 

 jungles in situ, in which considerable irregularities of outline 

 must in all probability have prevailed. 



On my own part, and that of my fellow-travellers in Russia, 

 I have brought before this Society what we consider strong 

 evidences against the too general adoption of this favourite 

 theory. We have told you that in many instances the Stlj- 

 mariajicoides occurs in loose and incoherent sands, as well as 

 in shales, and is frequently present where no coal is seen ; 

 but what we chiefly insist upon is, that all the coal-seams of the 

 south of Russia, without exception, alternate repeatedly wdth 

 beds of purely marine origin. In one section of the Donetz 

 coal-field it has been stated, that at least twelve beds of ma- 

 rine limestone alternate in one vertical section with thirteen 

 seams of coal and numerous bands of sandstone and shale, in 

 which many species of plants, besides Stigmarise, are confused- 

 ly heaped together. But we need not go to Russia for such 

 examples. The whole of the mountain limestone or lower 

 coal series of the north of England is charged, though not 

 to so great an extent, with proofs of the alternation of marine 

 deposits with coal and its associated sandstone and shale. 



The coast of Northumberland, to the north of Alnwick, 

 presents evidences of thin seams of coal resting at once on 

 sandstone, and intimately connected with limestone full of 

 sea-shells. Advancing northwards to Berwick, and to beyond 

 the Tweed, purely marine strata re-occur, charged with still 

 more carbonaceous matter ; and, in the same series on the 

 north-western parts of England, we have frequent examples of 

 the persistence of what must be called exclusively marine con- 

 ditions. Throughout that vast succession of beds, all the ani- 

 mal remains with which geologists have become acquainted, 

 occupying many distinct stages, have lived in the sea, whilst 

 the plants, so far as I have been able to observe them (broken 

 into fragments), consist of many species irregularly heaped 

 together, the whole, together with the sands, grits, pebbles, 

 and shale, offering the clearest signs of the drifting action of 

 water. 



On the subject, then, of the origin of coal, it would appear, 

 that as our inductions can never be sound, if they repose upon 

 one class of phenomena only, so do some coal strata offer in- 



