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speak, has recently been rendered fashionable, of the origin t)f coal 

 by subsidence of vegetable matter im situ, m:ViSt be considered esta- 

 blished as of general application. I, however, adhere to the cau- 

 tionary remarks which I ventured to make last yeai-, and will now 

 endeavour to impress upon your minds the inapplicability of such 

 a theory, however true under limitations, to large portions of the 

 carboniferous sti"ata in different parts of the Avorld. 



Since our last Anniversary statements have appeared in our own 

 country, both supporting and impugning the probable truth of 

 the theory. The last meeting of the British Association being held 

 at Manchester, geologists were there assembled in the centre of a 

 tract appealed to with great reason by the supporters of this theory 

 as containing many proofs of its truth ; for, in the immediate vici- 

 nity of that town there occur, as you all know, the beautiful examples 

 of vertical stems of large trees apparently in their original position, 

 which were formerly described before this Society. After giving an 

 elaborate and satisfactory account of the great Lancashire coal-field, 

 showing that its lowest members, formed on the flanks of the Penine 

 chain, and subordinate to the millstone grit, contain marine shells 

 analogous to those of the Mountain Limestone series, and stating 

 that they are surmounted by a middle and an upper grouj), the former 

 constituting the richest coal-field, Mr. Binney describes in great 

 detail the composition and contents of all the numerous roofs and 

 floors, as well as also of the coal-seams, which are included between 

 them. He shows also that the roofs vary in their nature at different 

 places, even over the same seam, and contain the remains of many 

 vegetables, sometimes,, as near Manchester, in vertical positions, 

 SigillaricB being in such cases a most abundant plant ; other roofs 

 of black shale in the lower field are loaded with Pectens.; Goni- 

 atites, Posidonia, and fishes. The coal-floors, on the contrary, pre- 

 sent a much greater uniformity of structure, fireclay similar to the 

 underclay of Mr. Logan being most abundant; though it is ad- 

 mitted, that a different or siliceous clay also frequently occurs, and 

 that two instances are known where the coal rests at once on coarse 

 quartzose sandstone. Seeing, that with one exception, all the floors 

 throughout an estimated thickness of near 5000 feet contain the 

 plant Stigmaria Jicoides usually with its leaves attached, — that both 

 the roofs and floors indicate a very tranquil method of accumulation, 

 — that the coal is free from admixture of foreign or drifted materials, 

 and that large trees frequently stand upright, this author is induced 

 to believe that the vegetables out of which, the coal has been formed, 

 grew upon the spot. 



■ At the same meeting this view was contested by Mr. W.C.William- 

 son, also well acquamted with the structure of the country around 

 Manchester. Mischief arguments were, howiever, derived from other 

 tracts, and they assisted in proving, — 1st, the frequent association 

 of marine shells with coal (as at Coalbrook Dale, and in Yorkshire); 

 2ndly, the very triturated and broken condition of the plants, as 

 well as their great intermixture in the sandstone and grits, coupled 

 with the fact that large quantities of vegetables are often matted 



