sumptuous material called Murrha was employed, which has been identified with fluor-spar, a translucent crystalline stone marked with blue, red, and purple, similar to the beautiful substance found near Matlock in Derbyshire.  Of this fluor-spar were formed the celebrated murrhine cups which were in use in Rome in the days of Pliny among the richest people, and for which fabulous prices were paid.  Several blocks of this material were found some years ago at the Marmorata which had been originally imported from Parthia in the reign of Hadrian.  One of them was employed by the Jesuits, when cut up into thin slices, in ornamenting the principal altar in the church of Il Gesu.  One of the chambers in the Baths of Titus was paved with slabs of the finest lapis lazula—­the Lapis Cyanus of the ancients—­derived from the spoils of the Golden House of Nero, and originally procured by order of the luxurious tyrant from Persia and the neighbourhood of Lake Baikal.  We can trace fragments of this exquisite pavement in the decoration of the chapel of St. Ignatius in the Church of the Jesuits.  The globe, three feet in diameter, over the altar, beneath which repose the remains of Ignatius Loyola, is sheathed with this most precious stone, whose brilliant blue, contrasting with the white marble of the group of the Trinity—­one of whose members holds it in His hands—­has a splendid effect.  The rare and costly marbles with which the Church of Il Gesu is profusely adorned were mostly taken from the ruins of the Baths of Titus by Cardinal Farnese in 1568.  From the same source came also the magnificent sarcophagus, sheathed with lapis lazula, under the altar of St. Ignazio, which holds the body of St. Luigi Gonzaga.

But it is impossible, within the limits of this chapter, to describe fully the relics of other precious and beautiful stones which may be found among the ruins of ancient Rome, or among the churches to which they have been transferred.  Profuse as were the ancient Romans in their general expenditure, upon no objects did they lavish their wealth so extravagantly as upon their favourite marbles and precious stones for the decoration of their public buildings and their private houses.  No effort was spared that Rome might be adorned with the richest treasures of the mineral kingdom from all parts of the world.  Slaves and criminals were made to minister to this luxury in the various quarries of the Roman dominions, which were the penal settlements of antiquity.  The antiquary Ficoroni counted the columns in Rome in the year 1700, and he found no less than eight thousand existing entire; and yet these were but a very small proportion of the number that must once have been there.  The palaces and modern churches of Rome owe, as I have said, all their ornaments to this passion of the ancients.  There is not a doorstep nor a guardstone at the corner of the meanest court in Rome which is not of marble, granite, or porphyry from some ancient