Marble-hunting is one of the regular pursuits of the visitor in Rome. The ground in almost every part of the ancient city is strewn with fragments of historical monuments. The largest and most valuable pieces have long since been removed by builders and sculptors, to fashion some Papal palace, or to adorn some pretentious church; and at the present day, in almost every stone-mason's shed, blocks of marble belonging to ancient edifices may be seen in process of conversion into articles of modern furniture. Many bits of the rarest kinds, however, still remain, which not unfrequently bear traces of the richest carving. For ages such spots have been quarries to visitors from all parts of the world, who wished to bring home some memorial of their sojourn in the Eternal City, and the supply is still far from being exhausted. That so much material should have survived the wholesale conversion, during the middle ages, of columns and statues into lime, in kilns erected where the temples and palaces were most crowded, and the vast exportation of objects of antiquity to other countries, is a striking proof of the prodigious quantity of marble that must have existed in ancient Rome. Now, however, such relics are more carefully preserved; and as the places where they are found in greatest quantity have been taken under the charge of the Government, and soldiers are constantly on the watch, it is not so easy as it used to be to abstract a fragment that has taken one's fancy.

Marble fragments are so eagerly sought after because they make most suitable and convenient souvenirs. Their own beauty and rarity, apart from all historical associations, are a great attraction. Many of them will form, when cut and polished by the lapidary, pretty tazzas and paper-weights, and even the smallest bits can be put together in a mosaic pattern, so as to make extremely beautiful table-tops. Whole rows of lapidary shops in the English quarter of the city, especially in the Via Babuino and the Via Sistina, are maintained by this curious traffic. In the Forum and Colosseum great quantities of marble and alabaster used to be found; but these localities have been so much ransacked that they now afford very scanty gleanings. The Baths of Caracalla and Titus, the recent excavations on the Esquiline, the ruins of the palaces of the Cæsars on the Palatine, and the open space marked out for new squares and streets between Sta. Maria Maggiore and St. John Lateran, are the best situations within the walls of the city. Outside the supply is almost as large as ever. All over the vast Campagna the foot of the wayfarer strikes against some precious or beautiful relic; and along the Appian and Latin Ways broken pieces of different kinds may be found in such profusion that such spots look like the rubbish-heap around a marble quarry. In the vast grounds over which the imposing ruins of Hadrian's Villa spread, heaps of fragments of marble flooring or casing may be seen in almost every neglected corner, from which it is easy to obtain some lovely bit of giallo antico or pavonazzetto or green porphyry. Beside the ancient quay of Rome, leading to the ruins of the Emporium or Custom-house—at a spot called in modern phrase "La Marmorata," because marble vessels still discharge their cargoes there—immense quantities of marble, alabaster, and porphyry are piled up, that were unshipped untold ages ago for Roman use; and a vineyard a short way off, on the slope of the Aventine, is much frequented by collectors on account of the richness of its finds.

But it is not as a mere amusement, or as a means of collecting pretty souvenirs of travel, that such marble-hunting expeditions are to be recommended. They may have a much higher value. The different kinds of marble collected are peculiarly interesting owing to their association with the different epochs of the history of the city and empire; and as the specimens which the geologist obtains throw light upon the formation of the rocky strata of the earth, so the small marble fragments which the student finds in Rome afford a clue to the various stages of its existence. Indeed, a competent knowledge of the marbles of Rome is indispensable to a clear understanding of the age of its ancient monuments. An immense amount of controversy has raged round some remarkable building or statue, which would have been prevented had the nature and origin of the marble of which it was composed been first investigated. The famous statue of the Apollo Belvedere in the Vatican, for instance, was long regarded as an original production either of Pheidias himself or of his school. But the discovery that the marble of which it is wrought is Lunar or Carrara marble—which was unknown until the time of Julius Cæsar, who first introduced it into Rome—is of itself a proof that it is not a genuine work of Greek art of the best period, but a monument of the decadence, or a copy of an original, wrought in imperial times for the adornment of a summer palace in Italy. In numberless other cases, ancient monuments have been identified by the mineral character and history of their marble materials. The first thing, therefore, which the student during his visit to the city ought to do, is to make himself acquainted with the different varieties of marble that have been found within the walls or in the neighbourhood. For this purpose the Museum in the Collegio della Sapienza or University of Rome will afford invaluable aid. In this institution, conveniently arranged in glass cases, are no less than 607 specimens of various marbles and alabasters used by the ancient Romans in the building or decoration of their houses and public monuments. The collection was made by the late Signor Sanginetti, Professor of Mineralogy in the University, and is quite unique. A great deal of instruction may also be obtained from the mineralogical study of the thousands of marble columns still standing in the older churches and palaces of Rome, most of which have been derived from the ruins of ancient temples and basilicas. Several excellent books may also be consulted with advantage—especially Faustino Corsi's Treatise on the Stones of Antiquity, Trattato delle Pietre Antiche, which is the most approved Italian work on the subject, and from which much of the information contained in the following pages has been obtained.

No marble quarries exist in the vicinity of Rome. The Sabine Hills are indeed of limestone formation, and large masses of travertine, a fresh-water limestone of igneous origin, occur here and there, but no mineral approaching marble in texture and appearance is found within a very considerable radius of the city. The nearest source of supply is at Cesi, near the celebrated "Falls of Terni," about forty-five miles from Rome, where "Cotanella," the red marble of the Roman States, is found, of which the great columns supporting the arches of the side aisles of St. Peter's are formed. The hills and rocks of Rome are all volcanic, and only the different varieties of eruptive rock were first employed for building purposes. The oldest monuments of the kingly period, such as the Cloaca Maxima, the Mamertine Prison, the Walls of Servius Tullius, and some of the earliest substructures on the Palatine Hill, were all built of the brown volcanic tufa found on or near their sites. This is the material of which the famous Tarpeian Rock and the lower part of most of the Seven Hills is composed. It is the oldest of the igneous deposits of Rome, and seems to have been formed by a conglomerate of ashes and fragments of pumice ejected from submarine volcanoes whose craters have been completely obliterated. It reposes upon marine tertiary deposits, and over it, near the Church of Sta. Agnese, where it is still quarried for building stone, rests a quaternary deposit, in which numerous remains of primeval elephants have been found. Though the Consular or Republican period was a very stormy one, and the reconstruction of the city, after its partial demolition by the Gauls, seems to have been too hurried to allow much attention to be paid to the materials and designs of architecture, yet there are numerous indications in the existing remains of that period that there was a decided advance in these respects upon the ruder art of a former age. Finer and more ornamental varieties of volcanic stone were introduced from a distance, such as the peperino or grayish-green tufa of the Alban Hills, the Lapis Albanus of the ancients, with its glittering particles of mica interspersed throughout its mass; the hard basaltine lava from a quarry near the tomb of Cæcilia Metella, on the Appian Way, and from the bed of the Lago della Colonna, once the celebrated Lake Regillus, to which the name of Lapis Tusculanus or Selce was given; and the Lapis Gabinus or Sperone, a compact volcanic concrete found in the neighbourhood of the ancient Gabii on the road to Tivoli, extensively used in the construction of the earliest monuments, particularly the Tabularium and the huge Arco de Pantani. Brick was also largely employed in the construction of the foundations and inner walls of public buildings, being arranged at a later date into ornamental patterns, to which the names of opus incertum andopus reticulatum were given; and in the manufacture of this substance, which they were probably at first taught by the Etruscan artificers of Veii in the neighbourhood, the Romans reached a high degree of perfection. The earliest tombs along the Appian Way were constructed of these different varieties of building materials. The sarcophagi of the Scipios were hollowed out of simple blocks of peperino stone; and the sculptor's art and the material in which he wrought were worthy of the severe simplicity of the heroic age.

But towards the close of the Republican period, Rome began to be distinguished for the magnificence of its public monuments. As its area of conquest spread, so did its luxury increase. New divinities were introduced from foreign countries, and domesticated in the Capitol; and these required more sumptuous fanes than those with which the native deities had been contented. The brown tufa of the Tarpeian Rock sufficed for the rude sanctuary of Vesta, the primitive hearth-stone of ancient Rome; but in the reconstruction of the sumptuous temple of Jupiter Capitolinus, which marked the grandest period of Roman history, the most precious stones of Asia and Africa were employed. Statues were imported wholesale from Greece to adorn temples and theatres, constructed after the models of Greek architecture, with pillars, friezes, and floors of precious Pentelic and Sicilian marble. During the last century of the Republic marble became a common building-stone. The tomb of Cæcilia Metella, and the temples of Ceres, Juno Sospita, and Castor and Pollux, indicate the introduction of this precious and beautiful material. But it was reserved for the period of the Empire to complete the architectural glories of the city. Travertine, usually called Lapis Tiburtinus, a straw-coloured volcanic limestone excavated in the plain below Tivoli, which has the useful property of hardening on exposure, was now used as the principal building-stone instead of the former lavas and tufas; and the Colosseum, entirely constructed of travertine, which was treated in the middle ages as a quarry, out of which were built many of the palaces and churches of Rome, attests to this day the beauty and durability of this material. Quarries of crystalline marbles, admirably adapted for the purposes of the sculptor and architect, were opened in the range of the Apennines overlooking the beautiful Bay of Spezia, in the vicinity of Carrara, Massa, and Seravezza, and largely worked in the time of Augustus. This emperor could boast that he had found Rome of brick, and left it of marble. The marbles of each new territory annexed to the Empire were brought at enormous expense into the Imperial City. A quay, to which reference has already been made, was constructed at the broadest part of the Tiber, where the vessels that transported marbles from Africa, and from the most distant parts of Eastern Europe and Western Asia, landed their cargoes. Here numerous blocks of marble were lately found, one of which was identified as that sent to Nero from a quarry in Carinthia; and another, a column of even more colossal dimensions, weighing about thirty-four tons of valuable African marble, was meant to serve as a memorial pillar of the Council of 1870 on the Janiculum, but the intention was never carried out. So abundant was marble during the first two centuries of the Empire, that it was nothing accounted of. Every temple, palace, and public edifice was built of it either in whole or in part. The tombs that lined the Appian Way on either side for fifteen miles had their brick cores covered with marble slabs; and their magnificence must have impressed every visitor who entered the Imperial City through this avenue of architectural glory shrouding the decays of death. It is obvious, then, that by studying the history of the conquests of Rome, the student can ascertain at what period a particular kind of marble was introduced from its native country, and the proximate date of the building in which this marble had been used.

It was a fortunate circumstance for the preservation of the precious marbles of Rome that Christianity laid its cuckoo egg in the nest of the Pagan city. When the capture of Rome by Alaric gave the final blow to heathen worship, by the overthrow of the ruling classes, who alone cherished the proud memories of the ancient faith, the greater number of the temples were still standing without any one to look after the edifices or maintain the religious services. The Christians were therefore free to take possession of the deserted shrines; and they speedily transferred to their own churches the columns and marble decorations that adorned the temples of the gods. Many of the precious stones that once beautified the palaces of emperors and senators were employed to form the altars and the mosaic flooring of the memorial chapels. Almost all the early churches were constructed on or near the sites of the temples, so that the materials of the one might be transported to the other with the least difficulty and expense, just as the settler in the back-woods of America erects his log-house in the immediate vicinity of the trees that are most suitable for his purpose. And the striking contrast between the plain, mean exteriors of the oldest Roman churches—rough, time-stained, and unfinished since their erection—and their gorgeous interiors, with their forests of columns separating the aisles, and the series of richly-sculptured and brilliantly-frescoed chapels, all blazing with gold and marble,—a contrast that reminds us of the surprising difference between the outside of a common clumsy geode lying in the mud, and the sparkling crystals in the drusic cavity at the heart of it,—would lead us to infer that the outer walls were raised in haste to secure the valuable materials on the spot, before they could be otherwise appropriated. Marangoni, a learned Roman archæologist, mentions thirty-five churches in Rome as all raised upon the sites and out of the remains of ancient temples; and no less than six hundred and eighty-eight large columns of marble, granite, porphyry, and other valuable stones, as among the relics of heathen fanes transferred to sacred ground within the city, when the bronze Jupiter was metamorphosed into the Jew Peter,

"And Pan to Moses lent his pagan horn."

Many of these relics can be traced and identified, for it may be generally presumed, for the reason already given, that none are very far removed from their original situation.

I know no more interesting pursuit in Rome than such an investigation; the objects, when their history is ascertained, acquiring a charm from association, over and above their own intrinsic beauty and interest. Most of the materials with which the three hundred and sixty-five churches of modern Rome have been constructed have been derived from the ruins of the ancient city. With the exception of a few comparatively insignificant portions brought from the modern quarries of Carrara, Siena, and Sicily, to complete subordinate details and to give a finish to the work, no marbles, it is said, have been used in ecclesiastical and palatial architecture for the last fifteen hundred years, save those found conveniently on the spot; and hardly a brick has been made or a stone of travertine or tufa hewn out for domestic buildings within the same period. The construction of St. Peter's itself involved more destruction of classical monuments than all the appropriations of previous and subsequent Vandals put together. Much has been lost on account of this extraordinary transmutation and reconsecration, whose loss we can never cease to deplore; but we must not forget at the same time that much has been conserved which would otherwise have wasted away under the slow ravages of time, been consigned to the lime-kiln, or disappeared in obscure and ignoble use. Enough remains to overwhelm us with astonishment, and furnish materials for the study of years.

The white marbles of Greece were the first introduced into Rome. Paros supplied the earliest specimens, and long held a monopoly of the trade. Marmor Parium, or Marmo Greco duro, as it is called by the modern Italians, is the very flower and consummation of the rocks. This material seems to have been created specially for the use of the sculptor—as that in which he can express most clearly and beautifully his ideal conceptions; and the surpassing excellence of ancient Greek sculpture was largely due to the suitability for high art of the marble of the country, which was so stainlessly pure, delicate, and uniform—as Ruskin remarks, so soft as to allow the sculptor to work it without force, and trace on it his finest lines, and yet so hard as never to betray the touch or moulder away beneath the chisel. Parian marble is by far the most beautiful of the Greek marbles. It is a nearly pure carbonate of lime of creamy whiteness, with a finely crystalline granular structure, and is nearly translucent. It may be readily distinguished from all other white marbles by the peculiarly sparkling light that shines from its crystalline facets on being freshly broken; and this peculiarity enables the expert at once to determine the origin of any fragment of Greek or Roman statuary. The ancient quarries in the island of Paros are still wrought, though very little marble from this source is exported to other countries. In the entablature around the tomb of Cæcilia Metella, which is composed of Parian marble, we see the first example in Rome of the use of ornaments in marble upon the outside of a building; an example that was afterwards extensively followed, for all the tombs of a later age on the Appian Way had their exteriors sheathed with a veneer of marble. The beautiful sarcophagus which contained the remains of the noble lady for whom this gigantic pile was erected, and which is now in the Farnese Palace, was also formed of this material. Most beautiful examples of Parian marble may be seen in the three elegant columns of the Temple of Castor and Pollux in the Roman Forum, belonging to the best period of Græco-Roman architecture; and in the nineteen fluted Corinthian pillars which form the little circular temple of Hercules on the banks of the Tiber, long supposed to be the Temple of Vesta. By far the largest mass of this marble in Rome is the colossal fragment in front of the Colosseum that belonged to the Temple of Venus and Rome; and it helps to give one an idea of the extraordinary grandeur and magnificence of this building in its prime, whose fluted columns, six feet in diameter, and the sheathing of whose outside walls of great thickness, were all made of Parian marble.

More extensively employed in Greek and Roman statuary and architecture was the Marmor Pentelicum, or Marmo Greco fino of the modern Italians. The quarries which yielded inexhaustible materials for the public buildings and statues of Greece, and for the great monuments of Rome, were situated on the slopes of Mount Pentelicus, near Athens; and after having been closed for ages, have recently been reopened for the restoration of some of the buildings in the Greek capital. The marble is dazzlingly white and fine-grained, but it sometimes contains little pieces of quartz or flint, which give some trouble to the workmen. The Parthenon, crowning like a perfect capital of human art the summit of Nature's rough workmanship in the Acropolis, was built of this marble; and the immortal sculpture of Pheidias on the metopes, the frieze of the cella, and the tympana of the pediments of the temple, known as the Elgin Marbles, were carved out of a material worthy of their incomparable beauty. Innumerable specimens at one time existed in Rome. The arch of Septimius Severus and the Arch of Titus are built of it, although the rusty and weather-beaten hue of these venerable monuments hides the nature of the material. Domitian, who restored the celebrated Temple of Jupiter on the Capitol, procured columns of Pentelic marble for the purpose from Athens; two of these are now in the nave of the church of Ara Coeli, built upon the site of the temple; and portions of the others, and of the marble decorations, were presented by the magistrates to the Franciscan friars of the neighbouring convent, and by them were wrought in 1348 into the conspicuous staircase leading to the façade of the church, which pious Catholics used to mount on their knees in the manner of the ancient worshippers of Jupiter. Among the statues wrought of this marble may be mentioned the famous group of the Laocoon found in the Baths of Titus; the beautiful Venus de Medici, discovered in the Villa of Hadrian, near Tivoli, and now in the Uffizi Gallery in Florence; and the well-known "Farnese Bull," sculptured out of a single block of huge dimensions, unearthed out of the ruins of the Baths of Caracalla, and now in the Museum of Naples. Massimo d'Azeglio, in his Recollections, gives an interesting instance of the value set upon this marble by modern Roman sculptors. Pacetti having purchased an ancient Greek statue of the best period in Pentelic marble, greatly mutilated, and wishing to repair it, could find nothing among the best products of the Carrara quarries to match the marble in purity and fineness of texture, and was therefore obliged to destroy another Greek statue of inferior merit in order to get materials for the restoration. From this combination he succeeded in producing the sleeping figure known as the Barberini Faun, whose forcible abduction by the Pontifical Government on the eve of its being sold to a German prince, so preyed upon the mind of the cruelly-wronged sculptor, that he took to his bed and died.

Very like Pentelic marble, but easily distinguishable, is the Marmor Porinum, the Marmo Grechetto duro of the Italians. It is intermediate in the quality of its grain between Parian and Pentelic marble, being finer than the former and not so fine as the latter. The column in front of the Church of Santa Maria Maggiore, removed by Paul V. in 1614 from the Basilica of Constantine, is composed of this species; as well as the celebrated Torso Belvedere of the Vatican, found near the site of the Theatre of Pompey, to which Michael Angelo traced much of his inspiration, and which, as we learn from a Greek Inscription at the base, was the work of the Rhodian sculptor Apollonios, who carved the group of the "Farnese Bull."

Not unlike this Porine marble was the Marmor Hymettium of the ancients; but it was never a great favourite in Rome on account of its large grain and dingy white colour, slightly tinged with green and marked by long parallel dark gray veins of unequal breadth. The metamorphic action was not sufficiently energetic to destroy the last traces of organic matter and the original stratification of the rock; and the crystallising force was not sufficiently exercised to allow of the entire rearrangement of the whole of the particles so as to expel the included impurities. This marble was not therefore fitted for sculpture; but it could be used for certain architectural purposes and for ornamentation. It used to be quarried extensively on Hymettus, the well-known mountain of Attica, celebrated for the quantity and excellence of its honey. The rock on which the aromatic flowers grew in such profusion for the bees, did not, however, partake of the same delightful quality. In working it a peculiar fetid odour of sulphuretted hydrogen, somewhat like that of a stale onion, was emitted, which gave rise to its modern Italian name—Marmo Cipolla. This repulsive quality, however, disappeared quickly on exposure. The finest specimens of this marble in Rome are the forty-six columns in the Church of St. Paul's, outside the gate, which belonged originally to the Basilica Æmilia in the Forum, founded about forty-five years before Christ, and were transferred to the new building when the venerable old church, in which they had stood for fifteen hundred years, was destroyed by fire. Nothing too can be finer than the two rows of Ionic columns of Hymettian marble which divide the immense nave of Santa Maria Maggiore from the side aisles. There are eighteen on either side, each upwards of eight feet in circumference, and are supposed to have been taken from the Temple of Juno Lucina, whose site is assigned by antiquaries to the immediate vicinity. Similar rows of fluted Doric columns of the same marble, ten on each side, adorn the Church of St. Pietro in Vincoli. They are ancient, and belonged to some temple or basilica of the Forum. There are also five ancient pillars of Hymettian marble in the upper Church of San Clemente, taken from the same prolific source. The wall which surrounds the unique choir or presbytery of this most interesting old church is also composed of great slabs of Hymettian marble, taken from the original subterranean church and hastily put together. Some of the ancient pillars of Hymettian marble belonging to the peristyle of the temple of Ceres and Proserpine, still as widely spaced as they used to be, adorn the Church of Santa Maria in Cosmedin, built on the foundation of that shrine; while twenty-four remarkably fine fluted Corinthian columns of the same material divide the triple nave of Santa Sabina on the Aventine, and are supposed to have belonged to the ancient Temple of Juno Regina, erected by Camillus after the destruction of the Etruscan city of Veii. Hymettian marble was one of the first—if not actually the first—species introduced into Rome. In the year of Rome 662, Lucius Crassus the orator brought to the city six columns of it, each twelve feet in height, with which he adorned his house on the Palatine Hill, receiving, on account of this circumstance, from Marcus Brutus the nickname of the Palatine Venus. At the present day the marble is used for corner-stones in the ordinary houses of Athens.

Another livid white marble, somewhat resembling the Hymettian, is that which is known to the Italians as Marmo Greco livido. It was called by the ancients Marmor Thasium, from Thasos, now Thapso, an island in the north of the Ægean Sea, off the coast of Thrace. The marble dug from the rocky sides of Mount Ipsario—a romantic hill thickly covered with fir trees, and rising three thousand four hundred and twenty-eight feet above the sea—enjoyed considerable reputation among the ancients. In Rome it must have been very common, if the name of Thasian is to be given to all the fragments of nondescript dusky white marble which are found among the ruins. Seneca says that the fish-ponds in his day were formed of that Thasian marble, with which at one time it was rare to adorn even temples. It was considered the least valuable of the white Greek marbles, and was used for the more ordinary purposes; Statius mentioning, in order to show the surpassing splendour of a particular building, that Thasian marble was not admitted into it. But there are not many well-defined monuments of it remaining in Rome. The chief are the bust of Euripides in the Vatican, and the outside casing of the pyramid of Caius Cestius, near the Protestant cemetery, now so weather-beaten and stained with dusky lichens that it is difficult to identify the material of which it is composed.

From this marble, by a slight tinge of yellow and a little darker shade, the livid white marble of Lesbos, the Marmor Lesbium, or Marmo Greco Giallognolo, may be distinguished. It is not a beautiful material; and yet, strange to say, the statues of some of the most beautiful women of antiquity, such as those of Julia Pia in the Vatican, and of the Capitoline Venus in the Museum of the Capitol, were made of this marble, obtained from the birthplace of Sappho. More beautiful is the kind known as the Marmor Tyrium, or the Greco-Turchinicchio, which has a light bluish tinge. It was shipped by the ancients at the port of Tyre from some unknown quarry in Mount Lebanon, which supplied the marble used without stint in the building and decoration of Solomon's Temple and Palace. In this quarry every block was shaped and polished before it was sent to be inserted in its place in the Temple wall, which therefore, as Heber beautifully says, sprang up like some tall palm in majestic silence. In Rome this marble was very rare. The doors in the great piers which support the dome of St. Peter's are each flanked by a pair of spirally-fluted columns of Tyrian marble, supposed to have been brought to Rome by Titus from the Temple of Jerusalem. They originally decorated the confessional of the old Basilica. The twenty-eight steps of the Scala Santa at the Lateran, said by ecclesiastical tradition to have belonged to Pilate's house in Jerusalem, and to have been the identical ones which our Saviour descended when He left the judgment-hall, are made of this marble; so that, whatever we may think of the tradition itself, there is a feature of verisimilitude in the material.

The chief supply of pure white marble in Rome was derived from the quarries in the mountains at Luna, an old Etruscan town near the Bay of Spezia, which fell to decay under the later Roman emperors. This ancient Marmor Lunense is called by the Italians Marmo di Carrara, because it is identical with the famous modern Carrara marble, and belongs to the same range of strata; the ruins of the ancient Luna being only a few miles from the flourishing town of Carrara, the metropolis of the marble trade. From Parian and Pentelic marble, Lunar marble, as already mentioned, can be easily distinguished by the less brilliant sparkle of its crystal facets, as shown by a fresh surface, and also by its more soapy-white colour. It is simply an ordinary Jurassic limestone altered by subsequent metamorphic action. The mountains which contain the quarries are highly picturesque, rising with serried outline to a height of upwards of five thousand feet, their flanks scarred by deep gorges and torrent-beds, and their lower slopes clothed with olive groves, vineyards, and forest trees. Lunar marble was first brought to Rome in the time of Julius Cæsar; and Mamurra, so bitterly reviled by Catullus, the commander of the artificers in Cæsar's army in Gaul, lined with great slabs of this marble the outside and inside of his house on the Coelian Hill—the first recorded instance of veneering or incrusting walls with marble. The discovery of this method of cutting marble into thin slices, and decorating structures of ordinary materials with them, was stigmatised by Pliny as an unreasonable mode of extending luxury. The use of Lunar marble, on account of its easy accessibility, speedily extended to every kind of building, public and private. So vast were the quantities sent to Rome, that Ovid expressed his fear lest the mountains themselves should disappear through the digging out of this marble; and Pliny anticipated that dreadful consequences would be produced by the removal in this way of the great barriers erected by Nature.

Many fine specimens still survive the ravages of ages, among which may be mentioned the eleven massive Corinthian columns, upwards of forty-two feet high, and four and a half feet in diameter, which form the peristyle of the Temple of Neptune in the Piazza di Pietra, well known as the old Custom-house. These pillars suffered severely from the action of fire, and are much worn and defaced, but there is a grandeur about them still which deeply impresses the spectator; and the blocks of marble which form the inner part of the architrave and entablature, as seen from the inner side of the court, are so stupendous that the ruins "overhang like a beetling rock of marble on a mountain peak." Grander still is the majestic column of Lunar marble dedicated to Marcus Aurelius, in the Piazza Colonna, which rears aloft its shaft one hundred and twenty-two feet in the air, wreathed around with spiral bands of historic reliefs, illustrating the Roman conquests over the German tribes north of the Danube. Very splendid specimens of the same marble may be seen in the three fluted Corinthian columns and a pilaster belonging to the Temple of Mars Ultor erected by Augustus in his Forum after the battle of Actium, which are the largest columns of any kind of marble in Rome, being eighteen feet in circumference, and upwards of fifty-four feet high. The two well-known pillars of the portico of the Temple of Minerva, called Le Colonnacce, belonging to the adjoining Forum of Nerva, are also composed of the same material; as also the three deeply-fluted Corinthian columns that remain of the Temple of Vespasian in the Roman Forum, which still retain some traces of the purple colour with which they appear to have been painted. By far the largest single masses of Lunar marble are the two portions of a gigantic frieze and entablature, highly ornamented with sculpture, one measuring one thousand four hundred and ninety cubic feet, and weighing upwards of one hundred tons, lying in the Colonna gardens on the slope of the Quirinal. These relics are supposed to have belonged to the splendid Temple of the Sun, which Aurelian erected after the conquest of Palmyra, and in which he deposited the rich spoils of that city. They are associated therefore with romantic memories of the famous Queen Zenobia, who spent her last days near Tivoli, after having been led captive in fetters of gold to grace the triumphal procession of her conqueror.

For statuary purposes Lunar marble was extensively used in ancient Rome. It formed the material out of which the sculptor produced some of the noblest creations of his genius. Of these the Apollo Belvedere in the Vatican collection is one of the most remarkable. The evidence of its own material, as already mentioned, has dispelled the old idea that it is one of the masterpieces of the Greek school; and Canova's conjecture, based upon some peculiarities of its drapery, is in all likelihood true, viz. that it was a copy of a bronze original, made, probably at the order of Nero, for one of the baths of the imperial villa at Antium, in whose ruins it was found in the fifteenth century. From the time of the Romans, the white marble of the Montes Lunenses has been used for decorative purposes in many of the churches and public buildings of Italy. It formed the material out of which Michael Angelo, Canova, and Thorwaldsen chiselled their immortal works. Its quality and composition, however, vary very considerably, and small crystals of perfectly limpid quartz, called Carrara diamonds, and iron pyrites, occasionally occur, to the annoyance of the sculptor. It becomes soon discoloured when exposed even to the pure air of Italy, but it is capable of resisting decay for very long periods. The opinion current in Paris, that the marbles of Carrara are unable to withstand the effects of the climate of that city, is due to the frequent use of inferior qualities, which are known to artists as Saloni and Ravaccioni, and whose particles have but a feeble cohesion, and consequently slight durability.

All the white marbles which I have thus described were used in Rome principally for external architecture; and beautiful as a city largely built of them may have looked, it must have had, nevertheless, a garishness and artificiality which would offend the artistic eye. When newly constructed, the Roman temples in the time of the emperors must have been oppressive, reflecting the hot sunshine from their snowy cellæ and pillared porticoes with an insufferable glare. Marble—unlike sandstones, clay-slates, and basalts, which are kindred to the earth and the elements, and find themselves at home in any situation, all things making friends with them, mosses, lichens, ivies—is a dead, cold material, and does not harmonise with surrounding circumstances. Like the snow, which hides the familiar brown soil from us, with its unearthly and uncongenial whiteness, its perpetual snow chills and repels human sympathies. Nature, for a similar reason, introduces white flowers very sparingly into the landscape; and their dazzling whiteness is toned down by the greenery around them, and the balancing of coloured objects near at hand, so that they do not in reality attract more notice than other flowers. The ancient Greeks themselves, keenly sensitive as they were to all external influences, had a fine instinct for this want of harmony between white marble and the tones of nature and the feelings of man; and therefore, in many instances, they coloured not only the marble buildings exposed to view outside, but even the marble statues carefully secluded in the niches within. The Parthenon was thus tinted with vermilion, blue, and gold, which seems to us, who now see only the golden hue with which the suns of ages have dyed its pure Pentelic marble, a barbarous superfluity, but which, to the people of the time, was necessary on account of the dazzling brightness of its material, concealing the exquisite beauty of the workmanship, and the finished grace of its proportions. Colour was used with perfect taste to relieve the sculptured details of the exterior, to articulate and ornament mouldings, and to harmonise the pure white temple with the dark blue sky of Greece and the rich warm tones of her landscape. The magnificent sarcophagi of white marble recently discovered at Sidon, belonging to the best type of Greek art, are most effectively adorned with different tints and gradations of red and purple, gold being sparingly applied. We see many traces of bright colouring on the columns and other parts of the buildings in the Roman Forum. The bas-reliefs on the Lumachella marble of Trajan's Column were originally picked out with profuse gilding and vivid colours; the egg and arrow moulding of the capital being tinted green, red and yellow, the abacus blue and red, the spirals yellow, the prominent figures gilt against backgrounds of different hues, and the water of the various rivers blue. Statues of the deities in Rome were nearly all coloured; and they received a fresh coat of vermilion—which, although it was the hue of divinity, was extremely fugacious—on anniversary occasions or in times of great national rejoicing.

All this pleads powerfully in behalf of Gibson's colour-creed, which has had so much prejudice to overcome. The beauty and expression of ancient sculpture, whether for outside or inside decoration, were greatly heightened by this tinting. In cases where it was not employed, Nature herself became the artist, and has burnt into the marble statue or the marble pillar the warm hue of life; and the rusty, withered look of the ruins, over which ages of change have passed, touches us more than the pure white marble structure could have done in the pride of its splendour, and appeals to the tenderest sympathies of beings who see in themselves, and in all around them, the tokens of death and decay. The graceful Corinthian pillars of the Temple of Castor and Pollux in the Forum, the three surviving witnesses of its former grandeur, are all the more suggestive to us by reason of the russet hues with which time has stained the snowy purity of their Parian marble; and it is difficult to say, as some one has shrewdly remarked, how much of the touching effect which the drooping figure of the Dying Gladiator of the Capitol produces upon us may be attributed to its discoloration, and to the absence of the dainty spotlessness of the original Greek marble. That grime of ages "lends a sort of warmth, and suggests flesh and blood," so that the suffering is not a cold and frosty incrustation, with which we have nothing to do, but a real tragedy going on before our eyes, by which our sympathies are most deeply moved. In a dry, hot climate, like that of Rome, there are no tender tones of vegetable colouring, no moss or lichen touches of gold or gray or green to relieve the bare cold surface, and the rigid formal outlines of the marble; but out of the sky itself the marble gathers the soft shadows and the rich brown hues that reconcile its strange, unnatural whiteness with the homely ways of the familiar earth. That wonderful violet sky of Rome would glorify the meanest object. The common red brick glows in its translucent atmosphere like a ruby; and the russet defaced column, as it comes out against its vivid light, becomes luminous like a pillar of gold. Brick and marble are of equal æsthetic value in this magic city, in which the uncomely parts and materials have a more abundant comeliness by reason of the medium through which they are seen. Over all things lingers permanently the transfiguring glow that comes to northern lands only in the afternoon. In that land it is always afternoon; the ruins bathe as it were in a perpetual sunset. The air is constantly flooded with a radiance which seems to transfuse itself through every part of the city, making all its ruinous and hoary age bright and living, forming pictures and harmonies indescribable of the humblest objects.

The white marbles hitherto described were principally for exterior use. But as Roman wealth and luxury increased coloured marbles were employed for internal decoration; and the effects which the Greeks obtained by the application of pigments, the Romans obtained by the rich hues of precious marbles incrusting their buildings, and durable as these buildings themselves. At first these rare materials were used with a degree of moderation, chiefly in the form of mosaics of small discs or cubes for the pavements of halls and courts. But at length massive pillars were constructed of them, and the vast inside brick surfaces of imperial baths and palaces were crusted over and concealed by slabs of rare and splendid marbles, the lines of which had no necessary connection with the mass behind or beneath. Carthage from the spoils of its temples supplied Rome with many of its rarest columns; and it is probable that not a few of these survive in the Christian basilicas that occupy the sites and were built out of the materials of the old Pagan structures. With the decay of the Roman Empire the use of coloured marbles in art increased, so that even busts and statues had their faces and necks cut in white and the drapery in coloured marble. It attained its fullest development in the Byzantine style, of which, as it appeals to the senses more by colour than by form, it is a predominant characteristic, necessary to its vitality and expression. The early Christian builders contemplated this mode of decoration for their interiors only. Very rarely had they the means to apply it to the outside surface, as in St. Mark's in Venice, which is the great type of the Byzantine church, coloured within and without with the rich hues of marbles and mosaics. Our great Gothic cathedrals, as an eminent architect has said, were the creation of one thought, and hence they were complete when the workmen of the architects left them, and their whole effect is dominated by one idea or one set of ideas; but the early Roman churches were the results of a general co-operation of associated art, and the large and plain surfaces of the interiors were regarded by the sculptor as a framework for the exhibition of his decorative art. Colour was lavished in veneers of rare marbles, and costly mosaics and frescoes covering the walls. There was thus "less unity of purely architectural design, but a greater amount of general artistic wealth."

Intermediate between the white marbles used for external architecture and the coloured marbles used for internal decoration, and forming the link between them, is the variety called by the Italians cipollino, or onion-stone. Its classical name is Marmor Carystium, from Carystos, a town of Euboea, mentioned by Homer, situated on the south coast of the island at the foot of Mount Oche. This town was chiefly celebrated for its marble, which was in great request at Rome, and also for its large quantities of valuable asbestos, which received the name of Carystian stone, and was manufactured by the Romans into incombustible cloth for the preservation of the ashes of the dead in the process of cremation. The asbestos occurs in the same quarries with this marble, just as this mineral is usually associated with talc schist, in which chlorite and mica are often present. Strabo places the quarries of cipollino at Marmorium, a place upon the coast near Carystos; but Mr. Hawkins mentions in Walpole's Travels that he found the ancient works upon Mount Oche at a distance of three miles from the sea, the place being indicated by some old half-worked columns, lying apparently on the spot where they had been quarried. This marble is very peculiar, and is at once recognised by its gray-green ground colour and the streaks of darker green running through the calcareous substance like the coats of an onion, hence its name. These streaks belong to a different mineral formation. They are micaceous strata; and thus the true cipollino is a mixture of talcose schist with white saccharoidal marble, and may be said to form a transition link between marble and common stone. It belongs to the Dolomitic group of rocks, which forms so large a part of the romantic scenery of South-Eastern Europe, and yields all over the world some of the best and most ornamental building-stones. In this group calc-spar or dolomite wholly replaces the quartz and films of argillaceous matter, of which, especially in Scotland, micaceous schist is usually composed. There are many varieties of cipollino, the most common being the typical marble, a gray-green stone, sometimes more or less white, with veins of a darker green, forming waves rippling over it like those of the sea. It occurs so often among the ruins that it must have been perhaps more frequently used in Rome than any other marble. It was also one of the first introduced, for Mamurra lined the walls of his house on the Coelian with it, as well as with Lunar marble, in the time of Julius Cæsar; but Statius mentions that it was not very highly esteemed, especially in later times, when more valuable marbles came into use.

One remarkably fine variety called Cipollino marino is distinguished by its minute curling veins of light green on a ground of clear white. Four very large columns in the Braccio Nuova of the Vatican, which may have belonged originally, like the two large columns of giallo antico in the same apartment, to some sumptuous tomb on the Appian Way, are formed of this variety, and are unique among all the other pillars of cipollino marble to be seen in Rome for the brightness of their colour and the exquisite beauty of their venation. Nothing can be more striking and beautiful than the rich wavelike ripples of green on the cipollino marbles that encase the Baptistery of St. Mark's in Venice, as if the breakers on the Lido shore had been frost-bound before they fell, and the sea-nymphs had sculptured them into the walls of this "ecclesiastical sea-cave." Indeed all the outside and inside walls of the glorious old church are cased with this marble—in the interior up to the height of the capitals of the columns; while above that, every part of the vaults and domes is incrusted with a truly Byzantine profusion of gold mosaics—fit image, as Ruskin beautifully says, of the sea on which, like a halcyon's nest, Venice rests, and of the glowing golden sky that shines above it. Line after line of pleasant undulation ripples on the smooth polished marble as the sea ebbs and flows through the narrow streets of the city. In the churches and palaces of Rome specimens of all the varieties of cipollino may be found, taken from the old ruins, for the marble is not now worked in the ancient quarries. The largest masses of the common kind in Rome are the eight grand old Corinthian columns which form the portico of the Temple of Antoninus Pius and Faustina in the Forum. The height of each shaft, which is composed of a single block, is forty-six feet, and the circumference fifteen feet. The pillars look very rusty and weather-worn, and are much battered with the ill-usage which they have received.

One of the most beautiful and highly-prized marbles of ancient Rome was the species which is familiar to every visitor under the name of Giallo antico. It must have existed in immense quantities in the time of the emperors, for fragments of it are found almost everywhere, and it is the variety that is most frequently picked up and converted into ornamental articles. It is easily recognised by its deep brownish-yellow colour, resembling somewhat the yellow marbles of Siena and Verona, though invariably richer and brighter. All the varieties are traversed more or less by veins and blotches of a darker yellow or brownish hue, which give them a charming variety. The texture is remarkably fine and close-grained. In this respect giallo antico can be distinguished from every other marble by the touch. When polished it is exquisitely smooth and soft, looking like ivory that has become yellow with age. No fitter material could be employed for the internal pavements or pillars of old temples, presenting a venerable appearance, as if the suns of many centuries had stained it with their own golden hue. From the fact that it was called by the Romans Marmor Numidicum, we are led to infer that this marble was quarried in Numidia, and was brought into Rome when the region was made a Roman province by Julius Cæsar. It was probably known to the Romans in the time of Jugurtha; but the age of luxury had not then begun, and Marius and Sulla were more intent upon the glories of war than upon the arts of peace. The quarries on the slopes of the Atlas, worked for three hundred years to supply the enormous demand made by the luxury of the masters of the world, were at last supposed to be exhausted; and the idea has long prevailed that the marble could only be found among the ruins of the Imperial City. But four or five years ago, the sources from which the Romans obtained some of their most precious varieties of this material have been rediscovered in the range of mountains called Djebel Orousse, north-east of Oran in Algeria. All over an extensive rocky plateau in this place numerous shallow depressions plainly indicate the existence of very ancient quarries. A large company has been formed to work and export the marble, which may now be had in illimitable quantity. The largest specimens of giallo antico existing in Rome are the eight fluted Corinthian pillars, thirty feet high and eleven feet in circumference, with capitals and bases of white marble, which stand in pairs within the niches of the Pantheon. In consequence of the fires of former generations, the marble has here and there a tinge of red on the surface. In the Church of St. John Lateran there is a splendid pair of fluted columns of giallo antico, which support the entablature over a portal at the northern extremity of the transept. They are thirty feet in height and nine feet in circumference, and were found in Trajan's Forum. In the Arch of Constantine are several magnificent giallo antico columns and pilasters, which are supposed to have belonged to the triumphal arch of Trajan. They are so damaged in appearance, and so discoloured by the weather, that it is not easy, without close inspection, to tell the material of which they are composed. For pavements and the sheathing of interior walls giallo antico was used more frequently than almost any other kind of marble; hence it is mostly found in fragments of thin slabs, with the old polish still glistening upon them.

It is difficult to describe, so as to identify it, the species of marble known as Africano. It has a great variety of tints, ranging from the clearest white to the deepest black, through yellow and purple. Its texture is very compact and hard, frequently containing veins of quartz, which render it difficult to work. Its ancient name is Marmor Chium, for it was brought to Rome from a quarry on Mount Elias, the highest summit in the island of Chios—the modern Scio—which contested the honour of being the birthplace of Homer. It received its modern name of Africano, not from any connection with Africa, but from its dark colour. It enters pretty frequently into the decoration of the Roman churches, though it is rare to see it in large masses. It seems to have been much in fashion for pavements, of which many fragments may be seen among the ruins of Trajan's Forum. The side wall of the second chapel in the Church of Santa Maria della Pace in the Piazza Navona is sheathed with large slabs of remarkably fine Africano, "with edges bevelled like a rusticated basement." In the Belvedere Cortile in the Vatican is a portion of an ancient column of this marble, which is the most beautiful specimen in Rome; and the principal portal of the portico of St. Peter's is flanked by a pair of fluted Roman Ionic columns of Africano, which are the largest in the city.

Closely allied to this marble is an ancient species which puzzles most visitors by its Protean appearance. Its tints are always neutral, but they vary in depth from the lightest to the darkest shade, and are never mixed but in juxtaposition. Dirty yellows, cloudy reds, dim blues and purples, occur in the ground or in the round or waved blotches or crooked veins. It has a fine grain and a dull fracture. This variety of Africano is known by the familiar name of Porta Santa, from the circumstance that the jambs and lintel of the first Porta Santa—a Holy Door annexed by Boniface VIII. to St. Peter's in the year 1300—were constructed of this marble. The Porta Santa, it may be mentioned, was instituted in connection with a centenary jubilee, but afterwards the period of formally opening it was reduced to fifty years, and now it is shortened to twenty-five. On the occasion of the jubilee, on Christmas Eve, the Pope knocks three times with a silver hammer against the masonry with which it is filled up, which is then demolished, and the Holy Door remains open for a whole twelvemonth, and on the Christmas Eve of the succeeding year is closed up in the same manner as before. A similar solemnity is performed by proxy at the Lateran, the Liberian, and the Pauline Basilicas. In all these great churches, as in St. Peter's, the jambs and Lintel of the Holy Door are of Porta Santa marble. This beautiful material was brought from the mountains in the neighbourhood of Jassus—a celebrated fishing town of Caria, situated on a small island close to the north coast of the Jassian Bay. From this circumstance it was called by the ancient Romans Marmor Jassense. Near the quarries was a sanctuary of Hestia, with a statue of the goddess, which, though unprotected in the open air, was believed never to be touched by rain. The marble, the most highly-prized variety of which was of a blood-red and livid white colour, was used in Greece chiefly for internal decoration. It was introduced in large quantity into Rome, and there are few churches in which the relics of it that existed in older buildings have not been adapted for ornamental purposes. Among the larger and finer masses of Porta Santa may be enumerated two columns and pilasters which belong to the monument of Clement IX., in the Church of Santa Maria Maggiore, and which are remarkable for their exceedingly fine texture and the unusual predominance of white among the other hues; four splendid Corinthian pillars, considered the finest in Rome, in the nave of Sta. Agnese; the pair of half columns which support the pediment of the altar in the Capella della Presentazione in St. Peter's; and the basin of the handsome fountain in front of the Pillar of Marcus Aurelius in the Piazza Colonna, constructed by the architect Giacoma della Porta out of an enormous mass of Porta Santa found lying on the ancient wharf.

Frequent specimens of a beautiful marble known as Fior di Persico, from the resemblance of the colour of its bright purple veins on a white ground to that of the blossom of the peach, may be found in the Roman churches. It was much used for mouldings, sheathings, and pedestals, and also for floors. In the Villa of Hadrian large fragments of slabs of this marble may be found, which lined the walls and floors of what are called the Greek and Latin Libraries. The Portuguese Church in Rome has several columns of Fior di Persico supporting the pediments of altars in the different chapels; especially four pairs of fluted ones which adorn the two altars at the extremity of the nave, which are among the largest and finest in Rome. But the most splendid specimens of all are a pair of columns in the Palazzo Rospigliosi. The dado, eight feet in height, in the gorgeous Corsini chapel in the Church of St. John Lateran, is formed of large tablets of highly-polished Fior di Persico, and the frieze that surrounds the whole chapel is composed of the same beautiful material, whose predominance over every other marble is the peculiarity of this sanctuary. The ancient name of this marble was Marmor Molossium, from a region in Epirus—now Albania—which was a Roman province in the time of Pompey. It is associated with the celebrated campaigns in Italy of Pyrrhus, king of Epirus, in which Greece was for the first time brought into contact with Rome. The region in which the quarries existed was the most ancient seat of Pelasgic religion.

The infinite hues and markings of the coloured marbles have all been painted by Nature with one material only, variously proportioned and applied—the oxide of iron. The varieties of marble are mainly caused by the different degrees in which this substance has pervaded them. They are variable mixtures of the metamorphous carbonates of protoxide of iron and lime. And it is an interesting fact that there is a distinct relation between deposits of magnetic iron ore and the metamorphoses of limestones into marbles; so that this substance not only gives to the marbles their colouring, but also their texture. Even the whitest saccharoidal or statuary marble, which it has not coloured, it has created by the crystallisation of the limestone associated with it. And the marbles of the entire province of the Apuan Alps owe their existence to the large quantities of iron ore disseminated throughout them, which have exercised a great influence on the molecular modification they have undergone. The same changes have been produced on the limestones of Greece and Asia Minor by veins containing iron ore running through them.

And of the marbles thus produced, one of the most beautiful is that which is known in Rome by the name of Pavonazzetto, from its peacock-like markings. The ground is a clear white, with numerous veins of a dark red or violet colour, while the grain is fine, with large shining scales. It resembles alabaster in the form and character of its veins, and in its transparent quality. It is a Phrygian marble, and was known to the ancients under the name of Marmor Docimenum. The poet Statius notices the legend that it was stained with the blood of Atys. It was a favourite marble of the emperor Hadrian, who employed it to decorate his tomb. It was brought to Rome when Phrygia became a Roman province, after the establishment of Christianity in Asia Minor. At first the quarry yielded only small pieces of the marble, but when it came into the possession of the Romans they developed its resources to the utmost; numerous large monolithic columns being wrought on the spot, and conveyed at great expense and labour to the coast. Colonel Leake supposes that the extensive quarries on the road from Khoorukun and Bulwudun are those of the ancient Docimenum. Hamilton, in his Researches, says that he saw numerous blocks of marble and columns in a rough state, and others beautifully worked, lying in this locality. In an open space beside a mosque lay neglected a beautifully-finished marble bath, once intended, perhaps, for a Roman villa; and in the wall of the mosque, and of the cemetery beside it, were numerous friezes and cornices, whose elaborately-finished sculptures of the Ionic and Corinthian orders proved that they were never designed for any building on the spot, but were in all probability worked near the quarries for the purpose of easier transportation, as is done in the quarries of Carrara at the present day. Pavonazzetto is thus associated in an interesting manner with the Phrygian cities of Laodicea and Colosse. When St. Paul was preaching the Gospel through this part of Asia Minor, the architects of Rome were conveying this splendid marble from the quarries of the Cadmus, to adorn the palatial buildings of the Imperial City. No marble was so highly esteemed as this, and no other species is so frequently referred to by the Latin poets.

The high altar of the subterranean church, under which the relics of St. Ignatius and St. Clement are supposed to lie, is covered by a canopy supported by elegant columns of pavonazzetto marble; while the high altar of the upper church is similarly surmounted by a double entablature of Hymettian marble, supported by four columns of pavonazzetto. The extra-mural church of St. Paul's had several splendid pillars of Phrygian marble, taken by the emperor Theodosius from the grandest of the law courts of the Republic; but these were unfortunately destroyed during the burning of the old basilica about sixty years ago. We see in the flat pilasters of this purple-veined marble, now erect against the transepts of the restored church, the vestiges of the magnificent Æmilian Basilica in the Forum, of whose celebrated columns Pliny spoke in the highest terms. Specimens of pavonazzetto are to be seen in almost every church in Rome. In the interesting old Church of Sta. Agnese there are two columns of this marble, the flutings of which are remarkable for their cabled divisions. The gallery above is supported on small columns, most of which are of pavonazzetto spirally fluted. In the Church of Santa Maria degli Angeli there is also a remarkably fine specimen; while there is a grand pair of columns in the vestibule of St. Peter's between the transept and the sacristy. Fourteen fluted columns of Phrygian marble have been dug up from the site of the Augustan Palace on the Palatine; while the one hundred and twenty employed by the emperor Hadrian, in the Temple of Juno and Jupiter erected by him, have been distributed among several of the Roman churches. The side walls of the splendid staircase of the Bracchi Palace are sheathed with a very rare and beautiful variety, remarkable for the delicacy of its veins and its brilliant polish. The veneer was produced by slicing down two ancient columns discovered near the Temple of Romulus Maxentius in the Forum, converted into the Church of SS. Cosma e Damiano. But the finest of all the pavonazzetto columns of Rome are the ten large ones in the Church of San Lorenzo outside the walls. In the volute of the capital of one of them a frog has been carved, which identifies it as having formerly belonged to the Temple of Jupiter or Juno, within the area of the Portico of Octavia. Pliny tells us that both temples were built at their own expense by two wealthy Lacedæmonian artists, named Sauros and Batrakos; and, having been refused the only recompense they asked—the right to place an inscription upon the buildings,—they introduced into the capitals of the pillars, surreptitiously, the symbols of their respective names, a lizard and a frog.

The most precious of the old marbles of Rome is the Rosso antico. Its classical name has been lost, unless it be identical, as Corsi conjectures, with the Marmor Alabandicum, described by Pliny as black inclining much to purple. For a long time it was uncertain where it was found, but recently quarries of it have been discovered near the sea at Skantari, a village in the district of Teftion, which show traces of having been worked by the ancients. From these quarries the marble can only be extracted in slabs and in small fragments. This is the case, too, with all the red marbles of Italy, which, in spite of their compact character, scale off very readily, and are friable, vitreous, and full of cleavage planes, in addition to which they are usually only found in thin beds, which prevents their being used for other purposes than table-tops and flooring-slabs. The predominance of magnetic iron ore, to which they owe their vivid colour, has thus seriously affected the molecular arrangement of the rocks. It is probable that rosso antico, like the Italian red marbles, belongs to one or other of the Liassic formations, which, in Italy as well as in Greece and Asia Minor, constitutes a well-marked geological horizon by its regular stratification and its characteristic ammonite fossils. The quantity found among the Roman ruins of this marble is very large; many of the shops in Rome carving their models of classical buildings in this material. But the fragments are comparatively small. When used in architecture they have been employed to ornament subordinate features in some of the grander churches. The largest specimens to be seen in Rome are the double-branched flight of seven very broad steps, leading from the nave to the high altar of Santa Prassede. Napoleon Bonaparte, a few months before his fall, had ordered these slabs of rosso antico to be sent to Paris to ornament his throne; but fortunately the order came too late to be executed. The cornice of the present choir is also formed of this very rare marble; while large fragments of the old cornice of the same material, which ran round the whole church, are preserved in the Belvedere Cortile of the Vatican. Tradition asserts that the pieces which have been converted to these sacred uses in the church once belonged to the house of Pudens, the father of its titular saint, in which St. Peter is supposed to have dwelt when in Rome. The entrance to the chamber of the Rospigliosi Palace, which contains the far-famed "Aurora" of Guido Reni on the ceiling, is flanked by a pair of Roman Ionic columns of rosso antico, fourteen feet high, which are the largest in Rome, although the quality of the marble is much injured by its lighter colour, and by a white streak which runs up each shaft nearly from top to bottom. In the sixth room of the Casino of the Villa Borghese the jambs of the mantelpiece are composed of rosso antico in the form of caryatides supporting a broad frieze of the same material wrought in bas-relief.

This marble seems to have been the favourite material in which to execute statues of the Faun; for every one who has visited the Vatican Sculpture Gallery and the Museum of the Capitol will remember well the beautiful statues of this mythic being in rosso antico, which are among their chief treasures, and once adorned the luxurious Villa of Hadrian at Tivoli. This marble is admirably adapted for such sculpture, for it gives to the ideal of the artist the warm vividness of life. And it seems a fit colour, as Nathaniel Hawthorne has said, in which to express the rich, sensuous, earthy side of nature, the happy characteristics of all wild natural things which meet and mingle in the human form and in the human soul; the Adam, the red man formed out of the red clay, in which the life of the animals and the life of the gods coalesce. In the Gabinetto of the Vatican, along with a large square tazza of rosso antico, is kept a most curious arm-chair of this marble, called sedia forata, found near the Church of St. John Lateran, upon which, in the middle ages, the Popes were obliged to sit at their installation in the presence of the Cardinals. This custom, which was practised as late as the coronation of Julius II. in 1503, arose from a desire to secure the throne of St. Peter from being intruded upon by a second Pope Joan—whether there ever really was such a personage, or whatever gave rise to the curious myth. The chair is like an ordinary library chair, with solid back and sides, sculptured out of a single block, and perforated in the seat with a circular aperture. Rosso antico is not what might strictly be called a beautiful marble. Its colour is dusky and opaque, resembling that of a bullock's liver, marked with numerous black reticulations, so minute and faint as to be hardly visible. But the grain is extremely fine, admitting of the highest polish.

Of black marbles—in the formation of which both the animal and vegetable kingdoms have taken part, their substance being composed of the finely-ground remains of foraminifera, corals, and shells, and their colour produced by the carbonaceous deposits of ancient forests—few kinds seem to have been used by the ancient Romans. The nero antico was the species most esteemed, on account of its compact texture, fine grain, and deep black colour, marked occasionally with minute white short straight lines, always broken and interrupted. It is the Marmor Tænarium of the ancients, quarried in the Tænarian peninsula, which forms the most southerly point in Europe, now called Cape Matapan. The celebrated quarries which Pliny eloquently describes, but for which Colonel Leake inquired in vain, were under the protection of Poseidon, whose temple was at the extremity of the peninsula. They attracted, on account of the sanctuary which the temple afforded, large numbers of criminals who fled from the pursuit of justice, and who readily found work in them. Very fine specimens of this marble may be seen in a pair of columns in the obscure Church of Santa Maria Regini Coeli, near the Convent of St. Onofrio, on the other side of the Tiber; in a pair in the church of Ara Coeli; and also in a pair in the third room of the Villa Pamphili Doria, which are extremely fine, and are probably as large as any to be met with. In consequence of the quantity used in the inscriptional tablets of monuments, for which this seems to be the favourite material, nero antico is extremely scarce in modern Rome. The bigio antico is a grayish marble, composed of white and black, sometimes in distinct stripes or waves, and sometimes mingled confusedly together. It was the Marmor Batthium of the ancients, and two of the large columns in the principal portal of the Church of Santa Croce in Jerusalemme are remarkably fine specimens of it, probably taken from the Villa of Heliogabalus, in whose gardens, called the Horti Variani, the church was built.

Another species is the bianco e nero antico, the Marmor Proconnesium of antiquity, obtained from the celebrated quarries of Proconnesos, an island in the western part of the Propontis. Many of the towns of Greece were decorated with this marble. The internal part of the famous sepulchre erected by Artemisia, the widow of Mausolus, king of Caria, to her husband, and after whom all grand tombs ever since have received the name of mausoleum, was built of this marble. So celebrated were the quarries of Proconnesos that the ancient name of the island was changed to Marmora, and the whole of the Propontis is now called the Sea of Marmora. Although so highly esteemed in Greece, this marble does not seem to have been extensively used in Rome; the finest relics being the four columns supporting the marble canopy, in the form of a Gothic temple, which surmounts the high altar of St. Cæcilia, which is among the most ancient of all the churches of Rome. They were probably derived from some old Roman palace, and are remarkable for the clearness and brilliancy of the white blotches on a black ground. There are different varieties of this marble: one kind in which the blotches or veins are pure black on a pure white ground, and another in which the blotches or veins are pure white on a black ground. In these varieties, however, the black and the white are more confused together, but remain notwithstanding distinct and separate, so that if the veins are white the ground is sure to be black, and vice versâ. The ancient Marmor Rhodium, or the giallo e nero, had golden-coloured veins on a black ground, and, owing to its compact texture, was capable of receiving a high polish. It is very like the celebrated marble of Portovenere, a modern Italian species obtained from the western hills of the Gulf of Spezia, where the formation passes into that of the ammonitiferous limestones of the Lias and of the palæozoic rocks. A beautiful highly-polished specimen of Rhodian marble exists in the mask in front of the tomb of Paul III. in the tribune of St. Peter's, sculptured by Della Porta in 1547, long previous to the discovery of the quarries of Portovenere. It may be remarked that the grain of the latter species is such that it will not keep its polish without extreme care; a circumstance which distinguishes it from the Rhodian marble, whose tenacity in this respect renders it eminently adapted for the more costly class of decorative works.

The marbles we have been hitherto considering belong to the older calcareous formations of Italy, Greece, Asia Minor, and Egypt, and go down to the upper triassic and muschel-kalk limestones, and perhaps even to those of an older period. But there is a class of ancient marbles in Rome of much more recent geological origin—belonging indeed to the Miocene epoch—which are called Lumachella, from the Italian word signifying snail, on account of the presence in all the species of fossil shells. They vary in colour from the palest straw to the deepest purple. Some of them are exceedingly beautiful and valuable, and they are nearly all more or less rare, being found chiefly in small fragments of ancient pavements. Their substance is formed of the shells of the common oyster in bluish gray and black particles on a white ground, as in the Lumachella d' Egitto; of the cardium or cockle, assuming a lighter or deeper shade of yellow, as in the Lumachella d' Astracane; of the ammonite, as in the L. Corno d' Ammone; of the Anomia ampulla in the L. occhio di Pavone, so called from the circular form of the fossils whichever way the section is made; of encrinites, belemnites, and starfish, showing white or red on a violet ground, as in the L. pavonazza; and "of broken shells, hardly discernible, together with very shining and saccharoid particles of carbonate of lime," as in the Marmor Schiston of the ancients—the brocatello antico of the Italians, so named from its various shades of yellow and purple, resembling silk brocade. The most important specimens of Lumachella marbles are the pair of very fine large columns of L. rosea on the ground-floor of the Schiarra Palace, the balustrade of the high altar of St. Andrea della Valle, two columns in the garden of the Corsini Palace of L. d' Astracane, and a pair of large pillars which support one of the arches of the Vatican Library, formed of L. occhio di pavone. Specimens of brocatello may be found in several churches and palaces, forming mouldings, sheathings, and pedestals.

The most interesting of the Lumachella marbles is the bianca antica, the Marmor Megarense of the ancients, composed of shells so small as to be scarcely discernible, and so closely compacted that the substance takes a good polish. The well-known Column of Trajan—the first monument (columna cochlæa) of this description ever raised in Rome, and far superior to the Antonine Column—is composed of Lumachella marble from Megara. It presents, in twenty-three spiral bands of bas-reliefs, winding round thirty-four blocks of stone, the history of the victories of Trajan over the Dacians, and, without reckoning horses, implements of war, and walls of cities, is said to consist of no less than two thousand five hundred figures, each about two feet two inches high. It is a strikingly suggestive thought, that this majestic pillar—which produced so deep an impression upon the minds of posterity that, according to the beautiful legend, Pope Gregory the Great was moved to supplicate, by means of masses in several of the Roman churches, for the liberation of him whom it commemorated from purgatory—should be composed of the relics of sea-shells.

"Memorial pillar! 'mid the wreck of Time,
Preserve thy charge with confidence sublime,"

said Wordsworth; but this sublime charge is committed to frail keeping. It is itself a sepulchre of the dead; and the tragedies of the Dacian war are inscribed upon tragedies that took place long ages before there was any human eye to witness them. The historic sculptures that so deeply move our pity for a conquered people, are based upon the immemorial sculptures of creatures whose sacrifice in whole hecatombs touches us not, because it is part of the order of the world by which life forms the foundation of and minister to life. It is strange how many of the grandest monuments are wrought out of the creations of primeval molluscs. The enduring pyramids themselves are formed of the nummulitic limestone studded with its "Pharaoh's beans," the exuviæ of shell-fish that perished ages before the Nile had created Egypt.

Of the breccias there is a great variety among the relics of ancient Rome. A breccia is a rock made up of angular pebbles or fragments of other rocks. When the pebbles are rounded the conglomerate is a pudding-stone. Marble breccias are formed of angular pieces of highly crystalline limestone, united together by a siliceo-calcareous cement, containing usually an admixture of a hornblendic substance, and which is due to a particular action of adjacent masses or veins of iron ore. The hornblendic cement, with its iron or manganese base, produces the variegated appearance which may be seen in specimens from different localities. As may be imagined from their composition, these rocks are as a rule extremely unalterable by ordinary atmospheric agencies, and are susceptible of a high degree of polish, which they retain with the utmost tenacity. They were favourite materials with the ancient Roman decorators; but they do not occur in large masses in the city. A beautiful pair of Roman Ionic columns under the pediment of the altar of the third chapel in the Church of Ara Coeli are made of a valuable breccia called Breccia dorata, distinguished by its small light-golden fragments on a ground of various shades of purple. The high altar of Santa Prisca on the Aventine is supported by one column of Breccia corallina of remarkably fine quality, in which the fragments are white on a ground of light coral-red. In the second chapel of St. Andrea della Valle there are two Corinthian columns of Breccia gialla e nera, which is an aggregate mass of yellow and black fragments: the yellow in its brilliant golden hue surpassing that of all other marbles, and forming a striking contrast to the long irregular black fragments interspersed throughout it. In the first chapel of the same church there are four fluted Corinthian columns of breccia gialla, containing small and regular blotches, of which the prevailing tint is orange, each fragment edged with a rim of deeper yellow that surrounds it like a shadow. A most beautiful variety of Breccia gialla e nera forms the basin of holy water at the entrance of the Church of St. Carlo di Catinari, in which "the colours resemble a golden network spread upon a ground of black"; and an exceedingly lovely urn is seen underneath the altar in one of the chapels of the Portuguese Church, in which white fragments are imbedded in a purple ground which shines through their soft transparency.

Not the least attractive objects in the chamber of the Dying Gladiator in the Museum of the Capitol area portion of a large column of very beautiful and extremely valuable Breccia tracagnina, in which golden-yellow, white, red, and blue fragments occur in very nearly equal proportions, and two large pedestals of Breccia di Sete-Bassi—so called from the discovery of the first specimens near the ruins of the Villa of Septimus Bassus on the Appian Way—containing very small purple fragments of an oblong shape, which is the characteristic peculiarity of all the varieties of this species of marble. Probably the most beautiful of all the ancient breccias is that called Breccia della Villa Adriana, from its occasional occurrence in the ruins of Hadrian's Villa, and also Breccia Quintilina, from its having been found in the grounds of the magnificent Villa of Quintilius Varus, commemorated by Horace, at Tivoli, now occupied by the Church of the Madonna di Quintigliolo. The prevailing colour of the fragments is that of a dark brown intermixed with others of smaller size, of red, green, blue, white, purple, bright yellow, and sometimes black, all harmonising together most beautifully. The comparatively small pieces found at Tivoli now adorn the Churches of St. Andrea della Valle, famous for its rich varieties of breccias, St. Domenico e Sisto and Santa Pudenziana, where they appear among the marble sheathing of the walls. In the chapel of the Gaetani in the last-mentioned church, the wall is incrusted with the richest marbles, especially Lumachella and Brocatello, and large tablets of Hadrian's breccia setting off the splendid sarcophagus of Breccia nera e gialla dedicated to Cardinal Gaetani.

Along with the breccias which I have thus incidentally noticed, but to which a whole essay might be devoted on account of their beauty, rich variety, and great value and rarity, should be classified a kind of "breccia dure," called Breccia d' Egitto. It is not, however, a true breccia, but a pudding-stone, composed, not of calcareous but of siliceous fragments; and these fragments are not angular, as in the true breccias, but rounded, indicating that they had been carried by water and consequently rounded by attrition. The connected pebbles must have been broken from rocks of great hardness to have withstood the effects of constant abrasion. In the Egyptian breccia are found very fine pebbles of red granite, porphyry of a darker or lighter green, and yellow quartz, held together by a cement of compact felspar. It has a special geological interest, inasmuch as it represents an ancient sea-beach flanking the crystalline rocks of Upper Egypt, where the cretaceous and nummulitic limestones end. The pebbles were derived from the central nucleus of granite from beyond Assouan to the upper end of the Red Sea, round which are folded successive zones of gneiss and schist pierced by intrusive masses of porphyry and serpentine. The pair of beautiful Grecian Ionic columns, and the large green tazza—eighteen feet in 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, employed by Hadrian in his villa, and which appears to have been brought from Terni, where it still exists in abundance. From the quarry near Volterra the Etruscans obtained the alabaster for their cinerary urns. The European alabasters are accumulated masses of stalactite and stalagmite, formed by the slow dropping of water charged with sulphate of lime, to which circumstance they owe the parallel stripes or concentric circles with which they are marked, while the rich and delicate varieties of colouring are produced by the oxides of iron which the water carries with it in its infiltration through the intervening strata. They are very soft and perishable, and consequently are very rarely found among the ruins of ancient Rome. The Oriental alabasters, on the other hand, which are distinguished from the European by their superior hardness and durability, are in reality not sulphates, but carbonates of lime. Their hardness is quite equal to that of the best statuary marbles. The ancient quarries on the hill—the modern Mount St. Anthony—near the town of Alabastron, in Middle Egypt, from which the material got its name, have only recently been re-opened, but blocks of large size and perfect beauty have been obtained. Owing to the facility with which alabaster can be reduced by fire to lime, very few large examples of it in Rome have escaped the ruthless kilns of the middle ages. The most interesting specimens of ancient alabaster are the very beautiful vase of Alabastro cotognino, prolate in form, and in colour white, streaked with very light pink, which contained the ashes of Augustus, found in the ruins of his mausoleum, and now in the Vatican; the bust of Julius Cæsar, made of the variety tartaruga, from the resemblance of its brownish-yellow markings to tortoise-shell, in the Museum of the Capitol; and the two large blocks of alabastro a pecorella, brought from the Villa of Hadrian, in the fourth portico of the Vatican, the largest and most beautiful specimens of this very rare alabaster in Rome, distinguished by white circular blotches, like a flock of sheep huddled together, on a deep blood-red ground. In the churches there are numerous specimens of all the varieties, forming the columns and sheathings of altars, memorial chapels, and monuments; the incrustations of alabaster on the walls of the Borghese chapel, in Santa Maria Maggiore, being conspicuous for their splendid effect. The baldacchino above the high altar of St. Paul's is supported by four splendid columns of Oriental alabaster presented to Gregory XVI. by Mehemet Ali, the viceroy of Egypt. An interesting collection of beautiful and valuable varieties of alabasters may be made in connection with the building operations still carried on in the unfinished façade of the basilica fronting the Tiber.

The well-known Verde antico is not a marble, but a mixture of the green precious serpentine of mineralogists and white granular limestone. It may also be called a breccia, for it is composed of black fragments, larger or smaller, derived from other rocks, whose angular shape indicates that they have not travelled far from the spots where they occur. The ancient Romans called it Lapis Atracius, from Atrax, a town in Thessaly, in the vicinity of which it was found. It can hardly be distinguished, except by experts, from the modern green marbles of Vasallo in Sardinia, and Luca in Piedmont. It occurs somewhat abundantly in Rome, having been a favourite material with the old Romans for sheathing walls and tables. Magnificent columns of it were introduced into the temples and triumphal arches. We find relics of these in the older churches. Four splendid fluted Corinthian columns of Verde antico, with gilded capitals, support the pediment of the high altar in Sta. Agnese, in the Piazza Navone, which formerly belonged to the Arch of Marcus Aurelius in the Corso. A pair of very fine columns of this precious stone flank each of the niches, containing statues of the twelve apostles, in the piers which divide the middle nave from the side ones in the Church of St. John Lateran. These twenty-four columns are remarkable for the clearness of the white, green, and black colours that occur in them. They are supposed to have been taken from the Baths of Diocletian. Two of the splendid composite columns which support the pediment of the altar in the Corsini chapel of this church are of this marble, and were also taken from the Arch of Marcus Aurelius in the Corso. One most magnificent column of Verde antico has been found, along with seven others of different marbles, in the wall of the narthex of the subterranean Church of San Clemente. A small portion of it is polished to show the beauty of the material, while the rest is dimmed and incrusted with the grime of age.

Very different from this is the ancient serpentine or ophite of Sparta called the Lapis Lacedæmonius, found in different hills near Krokee, or in Mount Taygetus in Lacedæmon, where the old quarry has recently been opened. It has a base of dark green with angular crystals of felspar of a lighter green imbedded in it. It is a truly eruptive rock, occurring in intrusive bosses, or in beds interstratified with gneiss and mica-schist, and owes its various shades of green to the presence of copper. Owing to its extraordinary hardness, this stone was seldom used for architectural purposes; and the lapidary will charge three times as much for working a fragment of this material into a letter-weight as for making it of any other stone. A pair of fluted Roman Ionic columns, supporting the pediment of the altar of the chapel of St. John the Baptist, in the Baptistery of St. John Lateran, are the only examples of ophite pillars in Rome. Next to these the largest masses are a circular tablet, forming part of the splendid sheathing of one of the ambones in the Church of San Lorenzo; and two elliptical tablets, still larger, engrafted upon the pilasters in front of the high altar of St. Paul's.

The principal use to which this stone was devoted in Rome was the construction of mosaic pavements. The emperor Alexander Severus introduced into his palaces and public buildings a kind of flooring composed of small squares of green serpentine and red porphyry, wrought into elegant patterns, which became very fashionable, and was called after himself Opus Alexandrinum. The infamous Heliogabalus had previously paved some of the courts of the Palatine with such intarsio work, but his cousin Alexander Severus, following his example, adorned with it all the terraces and walks around, and the pavements within, the isolated villas called Diætæ, dedicated to his mother Mammæa, which he added to the Palatine buildings. We have examples of this beautiful kind of tesselated pavement in some of the chambers of the Baths of Caracalla; and it is highly probable that the Opus Alexandrinum in the transept and middle nave of the Church of Santa Maria in Trastevere is in part at least contemporaneous with Alexander Severus, who conceded the ground on which the original oratory stood to Pope Calixtus I. in 222, for the special use of the Christians. If this be so, we have in this first place of Christian worship established in Rome the first instance of the application of Opus Alexandrinum to the decoration of a church. In the middle ages the fashion was beautifully imitated by artists of the Cosmati family and their school; and the mosaic pavements of this kind in the medieval churches of Rome are no older than this period. But we have reason to believe that the Opus Alexandrinum in two of the chapels of Santa Maria degli Angeli was taken from the Baths of Diocletian; while the splendid pavement of the whole church, naves, transept, and choir of Santa Croce in Jerusalemme, formed originally part of the decorations of the Sessorian Palace of Sextus Varius, the father of Heliogabalus, after whom the church is sometimes called the Sessorian Basilica. The flooring of the whole upper church of San Clemente was transferred from the older subterranean church, which derived its pavement from some of the ruins of the Palatine or the Forum; and the serpentine fragments, which enter very largely into the composition of the curious old mosaic floor of Ara Coeli must have had a similar origin as far back as the time of its founder, Gregory the Great. The Lapis Lacedæmonius must have been very abundant in Rome during the time of Alexander Severus—judging from the quantities that are made up into mosaics in the churches, and the heaps of broken fragments that are found on the Palatine and at the Marmorata. The circular space around the obelisk in the Piazza of St. Peter's to a considerable extent is paved with it; and specimens of it frequently occur among the ordinary road-metal in the city and neighbourhood.

Sicilian jaspers, so called, though really marbles, and purely calcareous, because of their resemblance in colour and form of the blotches to jasper, were wrought in great variety in the quarries in the neighbourhood of the celebrated Taormina, and were transported in the form of columns to Rome. Siliceous jaspers, obtained from the crystalline rocks of Asia Minor, Egypt, and Northern Italy, were also used for columns; and their brilliant red, green, and yellow hues, highly polished, contrasted beautifully with the white marbles of the interiors of the palaces. An even more sumptuous material called Murrhawas 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 building. Almost all the houses, as Raphael said, have been built with lime made of the costly old marbles. The very streets in the newly-formed parts of the city are macadamised with the fragments of costly baths and pillars. I took up one day, out of curiosity, some of the road-metal near the Church of Santa Maria Maggiore, and I identified in the handful no less than a dozen varieties of the most beautiful marbles and porphyries from Greece, Africa, and Asia. And when we remember that all these foreign stones were brought into Rome during the interval between the end of the Republic and the time of Constantine—a period of between three hundred and four hundred years—we can form some idea of the extraordinary wealth and luxury of the Imperial City when it was in its prime.