[ 537 ] 
But the moft remarkable and curious vein in thefe 
il;i ata is that, which they call the wood coal, or board 
coal, from the refemblance which the pieces have to 
the gi ain of deal boards. It is fometimes of a choco- 
late colour, and fometimes of a fhining black. The 
former fort feems to be lefs impregnated with bitu- 
men, is not fo folid and heavy as the latter, and has 
more the appearance of wood. It lies in ftrait and 
even veins, and is frequently dug in pieces of three 
or four feet long, and, with proper care, might be 
taken out of a much greater length. Other pieces 
ot the fame kind are found lying upon them, in all 
irections,. but without the lead: intermixture of 
eaith, or any other interftices, except fome fmall 
crevices, by which the pieces are divided from each 
other, in all directions. When it is firft dug, and 
moift, the thin pieces of it will bend like horn, but 
w en diy, it lofes its elafticity, and becomes fhort 
and cnfp. At all times,, it is eafily to be feparated. 
into very thin laminae, or fplinters, efpecially if it lie 
any time expofed to the heat of the fun, which, like 
tne fire, makes it crackle, feparate, and fall to pieces.. 
The texture of this foffil con lifts of a number of la- 
minae, or very thin plates, lying upon each other ho- 
rizontally, in which fmall protuberancies fometimes- 
appeal, like the knots of trees ; but,- upon examina- 
tion, tney are only mineral nuclei, which occalion. 
this interruption in the courfe of the laminae ; and 
pieces of ipar have been fometimes found in the 
middle of this wood coal. 
. Thon § h the texture of this coal is laminated yet 
it does not appear to have any of thofe fibrous inter- 
rections,. which are obferved in the grain of all wood.. 
This 
