So in the somewhat miscellaneous assortment of glass from many lands, and often of uncertain date, that we treat of in this chapter, it is this new wave of Oriental influence working upon the now decadent Roman types which gives in some measure a common note to objects otherwise so divergent. In another way the spread of the new religion had an even more direct and practical bearing on our subject-matter. If between the fourth and thirteenth century—between the later Gallo-Roman glass and the enamelled glass of the Saracens—there is in our collections a gap representing nearly a thousand years, only sparingly filled up by a few rare examples, the immediate cause is to be found in the abandonment of the practice of cremation, and of the habit of burying objects of value with the deceased. Fortunately for us, however, there was at first one important exception to this rule, and to this exception we owe the survival of so many specimens of a family of glass which is essentially both Christian and Roman, a family which should therefore rightly find its place at the commencement of the present chapter. [Illustration: _PLATE X_ GILT GLASS OF THE CEMETERIES 1. FROM COLOGNE. 2 AND 3. FROM ROME ] The GILT GLASS OF THE CEMETERIES is, indeed, strictly Roman, both in _provenance_ and in its artistic and technical relationships. The essential character of this early Christian glass depends upon the inclusion of a foil of thin gold between two plates of glass united by fusion. This is the principle of the decoration of the two bowls from Canosa that I have already described, and, indeed, in the technical difficulties overcome, and still more in artistic merit, these bowls far excel any later work of this class. As it is, the interest of these _vetri a fondi d’oro_, as the Italians call them, depends rather upon the fact that they constitute one of the earliest records of the art of the primitive Church, than upon any especial merit they may possess as examples of glass.[60] It is now well known that nearly all these little discs of glass have formed the base of tazza-shaped bowls, or of cups of conical form. Most of them have been extracted from the plaster in which they were embedded at the sides of the _loculi_, where in the passages of the catacombs the corpses were deposited. There is also a class of smaller medallions or studs, covered with thick lenticular glass, which were inserted round the body of a glass cup; in a few rare examples, chiefly from Cologne, the medallions remain in their original position on the cup (Pl. X.). These studs are sometimes of blue glass, and we are then reminded of a style of decoration in use in earlier times—blue bosses or ribs, _appliqués_ or fused into the body of the bowl.