d
sheep, were victims to the sudden fall of a bed of stones, thirty yards
deep, which descended from the summits of the Diablerets in Vallais. In
the year 1618, a portion of Mount Conto fell, in the county of
Chiavenna, in Switzerland, and buried the town of Pleurs with all its
inhabitants, to the number of 2430.

It is unnecessary to multiply examples of similar local catastrophes,
which however numerous they may have been in mountainous parts of
Europe, within the historical period, have been, nevertheless, of rare
occurrence when compared to events of the same kind which have taken
place in regions convulsed by earthquakes. It is then that enormous
masses of rock and earth, even in comparatively low and level countries,
are detached from the sides of valleys, and cast down into the river
courses, and often so unexpectedly that they overwhelm, even in the
daytime, every living thing upon the plains.

_Preservation of Organic Remains in Fissures and Caves._

In the history of earthquakes it was shown that many hundreds of new
fissures and chasms had opened in certain regions during the last 150
years, some of which are described as being of unfathomable depth. We
also perceive that mountain masses have been violently fractured and
dislocated, during their rise above the level of the sea; and thus we
may account for the existence of many cavities in the interior of the
earth by the simple agency of earthquakes; but there are some caverns,
especially in limestone rocks, which, although usually, if not always,
connected with rents, are nevertheless of such forms, and dimensions,
alternately expanding into spacious chambers, and then contracting again
into narrow passages, that it is difficult to conceive that they can owe
their origin to the mere fracturing and displacement of solid masses.

In the limestone of Kentucky, in the basin of Green River, one of the
tributaries of the Ohio, a line of underground cavities has been traced
in one direction for a distance of ten miles, without any termination;
and one of the chambers, of which there are many, all connected by
narrow tunnels, is no less than ten acres in area and 150 feet in its
greatest height. Besides the principal series of "antres vast," there
are a great many lateral embranchments not yet explored.[1041]

The cavernous structure here alluded to is not altogether confined to
calcareous rocks; for it has lately been observed in micaceous and
argillaceous s