a Deposit of bituminous IVood. 3i>5 



" This bituminous wood, which in some places appears 

 ahiiost uncovered, at the surface of the ground still retains 

 its primitive figure. In the course of the search which has 

 been made by digging, trunks of different thickness up to 

 two feet diameter have been dug up ; and among these there 

 are some compressed, which exhibit in their transverse sec- 

 tion an elliptical form. 



'^ The colour of this fossil is sometimes a perfect black, 

 Bometimes a grayish black, and sometimes a wood brown. 

 The blackest is sometimes pretty shining, and has even the 

 splendour of glass ; the erayish black, and brown, are dull, 

 but shine very much on being polished. 



" Its texture is entirely that of w ood, as it has not been 

 altered by the bitumen with which it is impregnated ; so 

 that in some pieces the tree to v.hich they belonged may 

 be determined : and in particular those which have the 

 transverse fracture conchoid and shining, and which are 

 perfectly black, exhibit all the characters of fir : others have 

 a texture similar to that of oak. 



" It is not so brittle as coal, and, when sawn in a direc- 

 tion perpendicular to the axis of the trunks, exhibits a solid, 

 compact, and very smooth surface. The concentric strata 

 of the fibres of which the trunk is composed may be easily 

 separated by introducing the point of anv instrument what- 

 ever. 



*' It readily kindles, and without the aid of any other 

 combustible: it gives in burning a lively and brilliant flame. 

 Tiie heat it produces is more intense and durable than that 

 of any other vegetable coal ; and, when once kindled, never 

 becomes extinct till entirely consumed, leaving very little 

 ashes. 'i"he combustion may be interrupted and renewed 

 at pleasure. 



" Lighter than coal, its specific gravity is to that of di- 

 stilled water as 1235 to lOCO : the fragments which exhibit 

 the characters of oak are still lighter. 



" SulphUret of iron is sometimes found in this fossil 

 disseminated in lumps and small grains, which when long 

 exposed to the air are decomposed, and cause the fragnients 

 to which they belong to fall in pieces. 



" It has besides the properties connnon to coal : but ii 

 naturalists have long entertained doubts respecting the ori- 

 gin of coals, in conie'-juence of the variety of their texture, 

 the irregularity of their form, their fragility, their strata 

 analoeous to those of schistous stones, Sec, tiie fossil oi 

 Castel Nuovo presents no dillicuily to their researches. The 

 uniforuiily of the tissue j the conslaiit direction of its fibres ; 

 X 3 tlic 



