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