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specimen, however, which I possess, from the neighbourhood of 
Wooburn, in Bedfordshire, has it in a considerable degree. 
The petrified wood found in the neighbourhood of Lough-Neagh, 
which has been spoken of in a former part of this volume, is evi- 
dently wood, which, having suffered bituminization, has afterwards 
been impregnated with silex, partially or totally, and in various 
degrees ; and has also, in some instances, become invested by the 
lapidified surrounding matrix. On examining a handsome specimen 
of the Lough-Neagh wood, in the British Museum, being of that 
kind which has been described as possessing the unchanged, conti- 
nuous with the petrified wood, I was convinced of its being bitu- 
minized wood, in some parts involved in, and in others adherent 
to, a coarse, hard, argillaceous matrix. Mr. Barton himself says, 
“ The smell (of the woody part of these stones) is not resinous, yet 
it is a strong smell, when it is burning in a large quantity ; and a 
faint smell of the same kind, when only the stone is burning ; per- 
haps, he says, this is the scent of bitumen^.” The other kinds of 
Lough-Neagh wood are undoubtedly of the silicious kind ; he says 
of them, “ They cleave like wood ; they contain abundance of fire, 
as may be proved by using them as flints, and by rubbing them one 
upon the other, even when they are wet; and they bear the fire 
surprisingly ; for although they are easily made red hot, yet they 
neither burn to lime, nor vitrify.” 
In Switzerland, and particularly in the neighbourhood of Bayern, 
beautiful specimens of the silicized bituminous wmod are found, 
bearing a very close resemblance to the recent wood in colour and 
figure. In Lithuania a rare kind is found, in which, though it ma- 
nifests no disposition to the transparency which the opaline wood in 
general shows, it possesses, in some parts, the opaline lustre, and has 
obviously, from the soft state in which it has existed, had its fibres 
* Lectures in Natural Philosophy, &c. by Richard Barton, B.D. Dublin, 1751, p. 89, &c. 
