Ves:etabUa in the Coal Measures. 215 



■■& 



which the rocks containing them are reached. These rocks 

 are almost always deep ; they are arrived at only by pits 

 and galleries, which are never much developed in many di- 

 rections. When forming the subterranean passages, the 

 eandstones are avoided as much as possible, as they only 

 •offer to the miner expense without profit ', yet these are the 

 rocks which appear to contain most of the vertical stems. 

 The difficulty of uniting all these conditions, ought to dimi^ 

 nish the number of circumstances favourable to the discovery 

 and easy and complete observation of these stems ; but ana* 

 logy leads us to believe that, if there was the same interested 

 motive in searching for them as the iron ore, they would be 

 found as generally spread over the coal measures as this ore. 

 jKTow, if these stems, still in their vertical position, shew 

 that the coal measures of St. Etienne, Saarbruck, &c. have, 

 been formed and deposited on the spots where these vege- 

 tables have lived, as much might and ought even from ana- 

 logy be said of all other coal measures. The arborescent 

 ferns and all the vegetables of a tropical aspect found buriedl. 

 in the coal measures must no longer then be sought to be 

 found beneath the torrid zone, nor to be brought into our 

 latitudes by means of great currents or grand debacles.. 

 This hypothesis, now almost entirely abandoned, is, as M., 

 Noggerath has particularly remarked, incompatible with a, 

 vertical and general disposition, which is so clear and so, 

 general. ; 



Yet M. de Charpentier, in the notice we have mentioned, 

 and which relates to the vertical trunk of Waldenburgy 

 offers very just reflections on the difficulty of conceiving that 

 these stems could grow in a rock such as that which now/ 

 envelopes them, and that this rock could deposit itself in the 

 middle of them during their growth, without in part der 

 stroying, upsetting, or at least deranging them. He sup- 

 poses that these vegetables, adhering by deep roots to the 

 ground, have been carried away with the soil that supported' 

 them, and left in the places where they are now observed. 

 He rests this explanation on a fact which he observed at the 

 ^i/ne of the great debacle of the lake of Bagne. In thi? 



