Chapter X: The Marbles of Ancient Rome (2)

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

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