circumference--the finest
specimen of Egyptian breccia to be seen in Rome, both in the Villa
Albani, and the vase of the same material in the chamber of Candelabra
in the Vatican, in which the prevailing green colour is crossed by
several stripes of pure white quartz, may thus have been sculptured
out of a portion of littoral deposit formed from the ruins of the
crystalline rocks of the mountain group of Sinai. There is something
extremely interesting and suggestive to the imagination in the twofold
origin of these conglomerate ornaments of the palaces of Rome. Around
them gather the wonderful associations of ancient human history, and
the still more awe-inspiring associations of geological history. They
speak to us of the conquests of Rome in the desolate tracts of Nubia
and Arabia, from which the spoils that enriched its palaces and
temples were derived; and of the existence of coast-lines, when Egypt
was a gulf stretching from the Mediterranean to the Mountains of the
Moon, which became silted up by slow accumulations. Their language, in
both relations, is that of ruin. They are survivors both of the ruins
of Nature and of Man, and are made up of the wrecks of both. Older far
than the marbles which keep them company in the sculptor's halls and
churches of Rome, and whose human history is equally eventful, their
materials were deposited along the shore of a vanished sea, when the
mountains that yielded these marbles lay as calcareous mud in its
depths.

Alabasters, of which there are numerous varieties, from pure
diaphanous white to the deepest black, were favourite decorative
materials with the ancient Romans. The different kinds were used for
the walls of baths, vases, busts, pillars, and sepulchral lamps, in
which the light shining through the transparent sides had an
agreeable softness. Cornelius Nepos, as quoted by Pliny, speaks of
having seen columns of alabaster thirty-two feet in length; and Pliny
says that he himself had seen thirty huge pillars in the dining-hall
of Callistus, the freedman of Claudius. One such column still exists
in the Villa Albani, which is twenty-two and a half feet in height.
The ancients obtained large blocks of alabaster from quarries in
Thebes in Egypt, in the neighbourhood of Damascus, and on Mount
Taurus. They imported some kinds also from Cyprus, Spain, and Northern
Africa. They obtained varieties nearer home, in different parts of
Italy, such as the beautiful Alabastro di Tivoli