the bed of the sea._--If to the
hundreds of human bodies committed to the deep in the way of ordinary
burial we add those of individuals lost by shipwrecks, we shall find
that in the course of a single year, a great number of human remains are
consigned to the subaqueous regions. I shall hereafter advert to a
calculation by which it appears that more than five hundred _British_
vessels alone, averaging each a burthen of about 120 tons, are wrecked,
and sink to the bottom, _annually_. Of these the crews for the most part
escape, although it sometimes happens that all perish. In one great
naval action several thousand individuals sometimes share a watery
grave.

Many of these corpses are instantly devoured by predaceous fish,
sometimes before they reach the bottom; still more frequently when they
rise again to the surface, and float in a state of putrefaction. Many
decompose on the floor of the ocean, where no sediment is thrown down
upon them; but if they fall upon a reef where corals and shells are
becoming agglutinated into a solid rock, or subside where the delta of a
river is advancing, they may be preserved for an incalculable series of
ages.

Often at the distance of a few hundred feet from a coral reef, where
wrecks are not unfrequent, there are no soundings at the depth of many
hundred fathoms. Canoes, merchant vessels, and ships of war, may have
sunk and have been enveloped, in such situations, in calcareous sand and
breccia, detached by the breakers from the summit of a submarine
mountain. Should a volcanic eruption happen to cover such remains with
ashes and sand, and a current of lava be afterwards poured over them,
the ships and human skeletons might remain uninjured beneath the
superincumbent mass, like the houses and works of art in the
subterranean cities of Campania. Already many human remains may have
been thus preserved beneath formations more than a thousand feet in
thickness; for, in some volcanic archipelagoes, a period of thirty or
forty centuries might well be supposed sufficient for such an
accumulation. It was stated, that at the distance of about forty miles
from the base of the delta of the Ganges there is an elliptical space
about fifteen miles in diameter, where soundings of from 100 to 300
fathoms sometimes fail to reach the bottom. (See above, p. 279.) As
during the flood season the quantity of mud and sand poured by the great
rivers into the Bay of Bengal is so great that the sea only