and that 40,000 plants of tobacco have been produced from
one individual. And as an instance of the actual dispersion
of vegetables, this accurate observer asserts that an American
plant, of the genus Erigeron, which was first brought into
Europe scarcely a century ago, and cultivated in the botanical
garden at Paris, had, in his time, spontaneously
spread itself over all France, Italy, Sicily, Flanders, and
Germany.
The neighbouring island of St. Paul is wholly covered with
an impenetrable thicket of coppice wood. Like Amsterdam
it is also of volcanie origin, and the shore is said to be surrounded
with pumice stone. It may, therefore, be reasonably
conjectured that of the two islands St. Paul is considerably
the earlier creation.
I t is observed by Yalentyn that, when William de Vlaming
visited this island in 1696, the pond (meaning the crater) was
separated by a ridge of rocks from the sea about twenty
paces, over which the seals clambered; that it was shaped
like a half moon, and about a pistol-shot in length. From
the description which I have just given it will readily be perceived
that a very material change has been effected in the
course of one hundred years, probably by some fresh eruption
having taken place. The same writer mentions likewise
a reef of rocks near the crater that jutted into the sea to
the distance of about a gun-shot, which at that time were
observed to be in a burning state. These were no doubt the
same as that of which the basaltic rock I have described
forms a part. This is still perfectly naked; and Vlaming
found only on the great island a few reeds, and here and
there among the rocks a very few plants that were not unlike
parsley. The whole island, indeed, wears every indication
of having been a very recent production of subterraneous ire,
which is still burning at no great distance from the sur ace.
Such at least appears to have been the case.. But geológica^
science is yet in its infancy. With all the various systems that
have been written to explain the structure, the constitution,
and the external appearances of the earth, and with all
aid which modem chemistry has lent to such investigations,
our real knowledge extends only to a very shallow depth below
the surface. One melts the globe by fire and throws
its most prominent features out of the ocean by the expansive
force of steam; another supposes that the regular and uniform
strata, observed in what has been called secondary
countries, could only have been effected by the agency of
water. Both may perhaps be right; and I dare say if Dr.
Hutton and Mr. Kirwan could examine the island of Amsterdam,
they would each of them produce it as an admirable
elucidation, one of the Plutonic and the other of the Neptunian
theory; for the materials have evidently undergone
complete fiision, and they are laid in regular and horizontal
strata.
Whether, indeed, it be admitted that stratified mountains
have been melted by heat or deposited by water, many o
them bear the most unequivocal proofs of having once been,
immersed under the ocean; and the grand question seems to
be reduced to this single point, whether the sea has retired
from them, or they have been raised oat ofAhc sea