n
every side, which has given to the place the old name of Campi
Leucogaei, and is the result of the metamorphosis of the trachytic tufa
by the chemical action of the gases that rise up through the
fumaroles, a very fine variety of porcelain--known to collectors as
Capo di Monti--used to be made on the hill behind Naples, and it has
been supposed that the china clays of Cornwall and other places have
been produced from the felspars of the granites in a similar way. The
whole of the Solfatara crater has been enclosed for the purpose of
manufacturing alum from its soil. On the hillside to the north there
are several caverns, called _stufe_, from whence gas and hot steam
arise, and these are used by the inhabitants as admirable vapour
baths. So late as the year 1538 a terrible volcanic explosion,
accompanied with violent earthquakes, happened not far from Puteoli,
which threw up from the flat plain on which the village of Tripergola
stood, a mountain called Monte Nuovo, four hundred and forty feet high
and a mile and a half in circumference, consisting entirely of ashes
and cinders, obliterating a large part of the celebrated Leucrine
Lake, elevating the site of the temple of Serapis sixteen feet, and
then depressing it, and generally changing the old features of this
locality. This eruption gave relief to the throes of Lake Avernus,
which henceforth ceased to send forth its exhalations, and became the
cheerful garden scene which we now behold.

Here on a small scale, in the very neighbourhood of man's busiest
haunts, occur the cosmical cataclysms which are usually seen only in
remote solitudes, and which during the unknown ages of geology have
left their indelible records on large portions of the earth's surface.
Here we are admitted into the very workshop of Nature, and are
privileged to witness her processes of creation. In the neighbourhood
of Rome the volcanoes are long extinct. Nature is dead, and there is
nothing left but her cold gray ashes. But here we see her in all her
vigour, changing and renewing and mingling the ruins of her works in
strange association with those of man--the ashes of her volcanoes with
the fragments of temples and baths and the houses of Roman senators
and poets. The whole region lies over a burning mystery, and one has
a constant feeling of insecurity lest the ground should open suddenly
and precipitate one into the very heart of it. Naples itself, strange
to say, a city of more than five