precipitate with oxalate of ammonia, reveal sulphate of lime, without
excluding the possibility of the chloride.

But how can these ashes do so much injury to the vegetation of the
ground they cover, especially at the first fall of rain? I think that
the damage is due partly to the sea-salt, and partly to the acids
contained either in the ashes or in the rain-water itself. Upon watering
the tender tops of some plants with a saturated solution of the salt
from Vesuvius itself, I noticed that they withered away after a few
hours. But very often the rain alone which traverses the smoke of
Vesuvius, or is produced by condensation from it, gives manifest acid
reactions, and destroys the grass and the tops of the trees. The
peasants believe that the rain is warm or of boiling water, from
observing that the tender parts of the plants are, by its deposit, all
burnt up. Vegetation is now recovering, but without flowers, and
consequently without fruit.

V.

THE CRATERS AND THEIR FUMAROLES.

The greater part of the lava issued from the base of the great fissure
in the cone which I have described; and although two other lava streams
descended from the top of the mountain, neither proceeded from the
crater, but from apertures near it. The great crater, divided in two as
already described, opened wide on the morning of the 26th April,
destroying the brim of the antecedent crater, and remaking it in another
shape with ejected matter, except on the south-west side, where the brim
was split. (See Plate 5.)

From this double crater, copious smoke, bombs and incandescent scoriae,
with ashes and lapilli, issued with violence, and from the depths below
came dreadful detonations and bellowings, producing great terror. And
yet the lava poured out into the Atria del Cavallo without any noise,
and not even a column of smoke marked its origin of issue--namely, from
the fissure.

When the eruption was over, the sight of the vertical walls of these
deep craters, of almost horizontal strata of scoriae and lithoidal
masses, with a fracture fresh, and as if they had never undergone the
action of fire or of acid vapours, without recent scoriae and without
fumaroles, was to me a marvellous spectacle. The fumaroles were almost
all on the brims of the craters, with emanations of hydrochloric and
sulphurous acid. In a few that were more removed from the brim,
sulphuretted hydrogen was perceptible. In the sublimations, chloride of
iron was