the pieces that are frequently dug up
in marfhes and fens, where not a
iingle buili is to be feen at prefent.
The fubftance, called by the natives
fnrturbrandy is likewife a clear proof
o f it.
This furturbrand is evidently wood,
not quite petrified, but indurated,
which drops afunder as foon as it
comes into the air, but keeps well in
water, and never rots : it gives a
bright though weak flame, and a
great deal o f heat, and yields a fourifli
though not nnwholefome fmell. The
fmiths prefer it to fea-coal, becaufe it
does not fo foon waile the iron. The
Icelanders make a powder o f it, which
they ufe to preferve their cloaths
from moths ; they likewife apply it
externally againil O the cholick. I have
feen tea-cnps, plates, &c. in Copenhagen
made o f furturbrand, that
takes a fine polifh. It is found in
many parts o f Iceland, generally in
the mountains, in horizontal beds ;
fometimes feveral on one another are
to be met with, as in the mountain o f
Lacks in Bardeftrand, where four ftrata
or
of furturbrand are found with alternate
beds o f different kinds o f ñones.
I have brought a large piece o f It
with me to Sweden ; it has evident
marks of branches, the circles of the
annual growth of the wood, leaves,
and bark, in the furronnding clay :
and there is fome reafon to believe,
that thefe trees have been mixed in the
lava thrown up by fome eruption o f
fire or by an earthquake.
I am almoil inclined to believe that
fome ilreams o f lava, which at the
depth o f fifteen feet, according to
obfervations that have been made, can
advance twelve thoufand Swedifli ells,
of two feet each, in eight hours, by a
declivity o f forty-five degrees, have
fwept away thefe trees, which feem to
have been o f a confiderable fize, and
buried them ; and this is fo much the
more probable, as the furturbrand frequently
has the appearance o f coal.
But as I do not know whether this opinion
has ever been advanced before,
and not having had opportunity oi*
making fufficient obfervations upon
this conjedlure, and as there is even
fome