SJÏowcfrak/ ¿¿& e&àïA/.
I do not think our present knowledge of the comparative anatomy
of timbers is sufficiently advanced to determine'. The sand is
calcareous, whether from the destruction of fragments of the
transition limestone (found beneath the basalt at St. Vicente) in
the bed of the ocean, or from comminuted shells, I will not venture
to pronounce, although I incline to the former opinion. The
carbonate of lime in the sheaths or envelopes of the wood, bears a
greater proportion to the silex than in our common mortar, than
which their substance is much harder; for estimating it by the
difference of weight after the escape of the gas, it amounted to 43
per cent. There is much ferruginous sand, mixed with that thus
thrown up, resulting from the destruction of the masses of red tufa
constantly falling from the cliffs into the sea. On the western
limit of this local deposit, are large globules of basalt (which from
their concentric form and other appearances have evidently been
in a fluid state), laying loose upon the soil, from the tufa (in which
they are still found imbedded at greater heights) having been
washed away from them. On such a soil the vegetation must be
■wretched; a mesembryanthemum and an orobus were the only
plants that existed, or rather languished there.
Having described this locality to the best of my ability, I leave
abler geologists to draw the conclusions; but perhaps I may be
allowed to su b m itF irst, that it, has evidently been an irruption
of the sea, from the heaps of terrestrial shells mingled with the
marine, and from the trees being found standing on their roots,
and not deposited promiscuously in detached fragments, or flattened,
as they would be, had they been transported thither, or
had they been subjected to any pressure of a superincumbent
stratum, afterwards removed. Secondly, it is clear that this must,
have happened after the Atlantic had lost that considerably higher
1 Specimens of these lignites have been sent to the Geological Society.