■k 1A11 lIki liIi
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35^ 1
caufes a little ebullition at firil, but
does not entirely diifolve it.
Your conjedure, Sir, concerning
the manner in which the furturbrand
is produced, does not feem improbable.
I have already obferved a long time
with furprize, that iiChes, orthocera-
tites, lituites, wood, &c . &c. which
are to be found in ilate, have been
compreifed or flatted, whilil they pre-
ie r v e their entire form and roundnefs
in lime-ilone.
This fame circumllance may be obferved
in the two pieces defcribed
above, efpecially in the larger, which
is only an inch and a half in thicknefs,
though it Is nineteen inches in length,
and thirteen in breadth. The outiide
o f it has no marks o f any roundnefs,
but is quite flat. Au exceeding great
weight is required to prefs a flick to
a ¿at plate; and I cannot conceive
how the moil immenfe beds, which
mnil neceflarily have been foft when
fpread over it, could ever produce
this eifea. The caufe of this is yet un-
difcovered, and will probably remain io
a long
r 3 5 7 J
a long time ; however fomething may
be found there which feems to ihew,
that the bituminous flate has been
produced in the fame manner, as it
has not only penetrated the inbilance
o f the ilate, but every thing elfe which
has been laid upon it, for it may yet
be obtained by means o f diflillation.
But by what means has this been
brought thither ? How could it be
imbibed by the clay, in cafe this was
under water, which however feems
to be undeniable, from the prodigious
number o f marine animals that are
found buried in it ? and how could
the inclofed bodies have been prefled
down horizontally ? All thefe problems
I cannot as yet anfwer fatisfac-
torily, much lefs explain with any degree
of certainty.
14. Very coarfe, heavy, and hard
lava, full o f bladders, almoil black,
intermixed with white grains re-
fembling quarz, which in fome places
have a figure not unlike a fquare.
The black matter is not at trailed
by the magne t ; but i f a piece o f it is
Z 3 held
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