[ 207 J 



XVII. — Notice I'espectmg a Piece of Recent Wood partly petrified by 

 Carbonate of Lime, with some Remarks on Fossil Woods. 



By CHARLES STOKES, Esq, F.G.S. 



[Read June 8, 1836.] 



IhROUGH the kindness of Mr. Heuland I have lately received a collection 

 of fossil woods from Germany, that gentleman having very obligingly engaged 

 one of his correspondents to attend to the particular inquiries I wished to 

 make, and to collect for me the objects described. 



To this collection was added a specimen of recent wood in which some 

 portions have become petrified by carbonate of lime ; and although this is not 

 the first known instance of the occurrence of wood partly petrified by calca- 

 reous spar, yet it has, from its peculiarity, led to comparisons with some 

 other fossil woods of remarkable appearance, both calcareous and siliceous, 

 and for which it appears to have afforded some explanation. I am induced 

 to submit to the Geological Society the following observations respecting it, in 

 the hope, that by exciting attention and remark from other observers, we may 

 obtain some knowledge on the very difficult question of the process of petri- 

 fication. 



This piece of wood is of the common beech (Fagus si/lvatica), and was 

 found by M. Cotta of Tharand in an ancient Roman aqueduct at Eilsen in 

 the principality of Lippe Buckeberg, but I understand that he has not pub- 

 lished any account of it. 



The size of the portion in my possession, is about 3\ inches by 4^, and the 

 thickness is nearly one inch. For the better understanding of the description, 

 the accompanying drawing has been made of the specimen (Plate XVI. fig. 1). 



The wood is, for the most part, in the state of very old dry wood, but there 

 are several insulated portions, in which the place of the wood has been taken 

 by carbonate of lime. These portions, as seen on the surface of the horizontal 

 section, are irregularly circular, varying in size, but are generally a little 

 less or more than \ of an inch in diameter, and they run through the whole 

 thickness of the specimen in separate, perpendicular columns. 



The vessels of the wood are distinctly visible in the carbonate of lime, and 



