446 



grounds ; or whether it results from that arrangement in the ever 

 admirable economy of nature, by which her multifarious opera- 

 tions are carried on, without any injurious interference with each 

 other. That the latter is the case will, I trust, appear, from a slight 

 attention to the following observations. 



No circumstance has ever been remarked which will authorize 

 the supposition, that vegetable matter can be liable to the bitumi- 

 nous change, until deprived of all the energies of vegetable life. 

 But roots, as is well known, long retain their vegetative powers 

 after entire separation from their trunk. The trunk, indeed, soon 

 ceases to live ; but the root will be found, after a long period, to be 

 alive: feeding on its own juices, and at last terminating this mode 

 of existence, by changing into a soft pithy substance, which soon 

 resolves into vegetable earth (Vegetabilia terrificata, Waller). Hence 

 it appears, that, after separation from the bodies which they sup- 

 ported, the roots of trees continue to possess those powers, which 

 most strongly oppose the bituminous change ; and when deprived 

 of these powers, they have suffered such an exhaustion of their 

 principles, that their resolution into almost mere earth speedily 

 follows. 



It is observed by Liebknecht, when speaking of the ferruginous 

 tree found in Laubac, that, although the greatest care and industry 

 was employed, only very few pieces were found which had the ap- 

 pearance of roots ; and even these, he acknowledges, bore very few, 

 if any, decided marks of having originally existed in that state*. 



Plate VI. Fig. 27, appears to have been part of a small branch 

 or twig of some tree. Fig. 29, has by some been thought to be a 

 spike of some grain, and by others the spine of an Echinus ; but 

 this, perhaps, is of the same origin as the former. The substance 

 represented at Fig. 28 of the same Plate, is a small silicious boulder, 



Discursus de Diluvio maxirao, &c. a Jo. Georgio Liebknecht, cap. iii. ect. 22. p. 385. 



