Mr. Hatcuett’s Obfervations on Bituminous Subflances. 1% 
59 
properties of wood; and that thefe ftrata do not exhibit any of 
thofe irregularities on their furfaces, which might be expected, 
on the fuppofition that they were formed by the roots, trunks, 
and branches of trees long buried in the earth. It is alfo dif 
ficult to imagine wood to have been tranfported and depofited in 
this place at feventeen different periods, and yet it muft be allowed 
that thefe ftrata have been formed by fucceffive operations. I mutt 
confefs, that after having twice vifited and examined the fpot 
exprefsly for the purpofe, I ftill find myfelf utterly unable to offer 
any opinion upon the fubjeét. 
‘The charaéters of bitumen are but little apparent in the Bovey 
coal, and the fuperior {trata even appear to have Joft a portion of 
their combuftible principle, while the inferior ftrata poflefs it. The 
lower parts alfo of thefe ftrata are more compact and more com- 
buftible than thofe parts which are immediately upon them *. 
Another remarkable fort of foffil wood, which much refembles 
the Bovey coal,.and in like manner is arranged among the bitumi- 
nous woods, is that found in Iceland, which is called by the inha- 
bitants Surturbrand. This is rather harder thau the Bovey coal, 
but in every other refpe& is the fame. It alfo forms ftrata many 
feet ‘in thicknefs ; but it is very extraordinary that thefe ftrata 
appear to be formed of trunks of trees, which, in hee tranf{verfe 
* At about 100 yards to the weft of the pits, is a bog of confiderable extent, where 
peat is cut, and decayed roots and trunks of trees are found, which do not, however, in 
the leaft approach to the nature of the Bovey coal. - Whether this bog has been in any 
manner connected with the formation of the above-mentioned {ubflance, I do not pretend 
to determine. 
A yellowith brown compact fubftance, which in colour and fraQure refembles ferrut 
ginous clay, is alfo found occafionally with the Bovey coal: it is brittle, and is high:y 
inflammable; it melts like a bitumen, and emits a fmoke which in fmell refembles amber. 
This fubftance is but rarely found. 
‘ Tr 2 fe“tion, 
