Skihnarine Foreji on the eafl Coajl of England. 219 



fited there by any of the aitln;^; f ■ .- under the prefent conftitution of nature. The form- 

 atirn, indeed, of tkj very mountains in which they are buried, and the nature aid difpofi- 

 tion of tiie materials which compofe them, are fuch as we cannot account for by any of tha 

 a<Stionsand re-aftions which in the a6lual ftate of things take place on the furface of the earth. 

 We muft neceffarily recur. to that period in the hiflory of our p'anet, when tlie furface of 

 the ocean was at leaft (o much above its prefent level, as to coyer even the fummits of thefe 

 feccjndary mountains, which contain the rem.iins of tropical plants. The changes which 

 thefe vegetables have fufFered in their fubftance, is almoft total. • They commonly retain 

 only the external configuration of what they originally were. Such is the ftate in which 

 they have been found in England by Llwyd ; in France by JufSeu ; in the Netherlands by 

 Burtin^ not to mention inflances in more diftant countries. Some of the impreffioiis, or 

 remains of plants, found in foils of this nature, which were, by more ancient and lefs 

 enlightened oryftoiogifts, fuppofed to belong to plants actually growing in temperate and cold 

 climates, fcem, on accurate inveftigation, to have been parts of exotic vegetables. In tact, 

 whether we fuppofe them to have grown near the fpot where they are found, or to have 

 been carried hither from difFerent parts by the force of an impelling flood, it is equally diffi- 

 cult to conceive how organized beings, which, in order to live, require fuch a vaft dffcrencc 

 in temperature and in fcafons, could live on the fame fpot, or how their remains could (from 

 climates fo widely diftant) be brought together to the fame place by one common diflocat- 

 rng caufe. To this ancient order of foilil vegetables, belong whatever retains a vegetable 

 fhape, found in or near coal mines ; and (to judge from the places where they have been 

 found) the greater part of the agatized woods. But from the fpecies and prefent ftate of 

 the trees, which are the fubject of this memoir, and from the fituation and nature of the foil 

 in which they are found, it feems very clear that they do not belong to the primeval order 

 of vegetable ruins. 



The fecond order of foffil vegetables comprehends thofe which are found in the ftrata of 

 clay, or fand ; materials which are the refult of flow depofitions of the fea or of rivers; 

 agents ftill at work under the prefent conftitution of our planet. Thefe vegetable remains 

 are found in fuch flat countries, as may be confidered to be of a new formation. Their ve- 

 getable organization ftill fubfifts, at leaft in part ; and their vegetable fubftance has fufFered: 

 a change only in colour, fmell, or confiftence ; alterations which are produced by the deve- 

 lopement of their oily and bituminous parts, or by their natural progrefs towards rottennefs. 

 Such are the foflil vegetables found in Cornwall by Borlafe ; in EfTex by Derham ; in York- 

 fliire by de la Pryme and Richardfon ; and in foreign countries by other naturallifts. Thefe 

 vegetables are found at different depths, fome of them much below the prefent level of the 

 fea, but in clayey or fandy ftrata (evidently belonging to modern formation), and have no 

 doubt been carried from their original place, and depofited there by the force of great rivers 

 •r currents, as it has been obferved with refpedl to the Miffiflippi *. In many inftances^ 



• La Condreniere for les Depots du Miffiffippi. Journ, de Phyf. vol. XXI. p. 230. 



however,, 



