In all great eruptions the flow of the lava is preceded by the
ejection of vast quantities of volcanic dust, ashes, dross, slag,
and loose stones. These are tossed into the air with tremendous
violence, consequently, to a great height. The stones thus ejected
are sometimes of immense size. A rock, whose weight is estimated at
two hundred tons, was thrown from the summit of Cotopaxi to the
distance of more than ten miles. Large stones have been tossed up
by Vesuvius to the estimated height of three thousand six hundred
feet. The dust of the volcano of St. Vincent was carried more than
two hundred miles to the eastward in the teeth of the trade wind;
consequently it must have been thrown to an enormous height, in
order to its falling at so vast a distance from its source.

Besides the usual volcanic dust and ashes, there is sometimes
thrown from the crater of a volcano a substance resembling spun-
glass or asbestos. It possesses the flexibility and lustre of silk.
The volcano of Salazes, in the Island of Bourbon, is remarkable for
this substance, and it has there been seen to form a cloud covering
the entire surface of the mountain. But it has also been found in
other places. How curious it would be to have this volcanic silk
spun into threads, and knitted into stockings or woven into a
garment! Who can tell what may happen in these days of adventure
and invention? Who knows but what some young reader, whose eye is
now resting on this page, may yet live to present his ladylove with
a pair of knitted gloves composed of the volcanic silk of Salazes?

Great as the contrast is between this filmy material and the
ponderous blocks tossed into the air by Cotopaxi and Etna, it is
not greater than that between the latter and other masses which
have from time to time been upheaved by volcanic forces. Instances