OF FOSSILS. 



I have in rry pcffeffion fomc pfcudogalcna of 

 u blackifli yellow, united to millcporcs. 



CLXXI. Species of Pbhgi/licatcd organic Fojpls. 



WOOD impregnated with petroleum frequent- 

 ly occurs. Tlicre is a trunk of a tree in the col- 

 lection of the academy at Upfal, indurated with 

 ])ctroleum, black and fmooth, and yet eafily 

 diilinguiflicd to be of a beech. The Icelandic fof- 

 111 wood alib comes under this head, of which 

 I have fpokcn more fully in another place *. 



Bones penetrated with afphaltus are fome- 

 times found. 



As is foiTil wood likcwife, whofe pores arc fil- 

 led with amber, and even with infects and other 

 final 1 animals; which this fubftuncc docs not on- 

 ly penetrate, but even furrounds, as :i fplcndid 

 monument covering their remains. 



Turf and mould contain organic bodies, cfpC- 

 cially of vegetables reduced in the greatcll part 

 by putrefaction to dull; but which difplay iigns 

 of their original ftruchirc and charader, more 

 or lefs obfcure. The firft fcarce diflers from tho 

 latter but in the greater decompofition and den- 

 fity of its mafs* 



T 2 VARIITIES, 



EfTays, v. iii. p. 239 



