[Footnote 94: They are to be seen in a little portable altar; and are most probably the proofs of some niello worker of the time; who had executed those histories in silver to ornament some similar little altar, or the place in which sacred relics were laid. Before introducing the niello, he had cast proofs of his work in these zolfi (sulphurs), which were subsequently inlaid with great symmetry and taste in the altar-piece. They consist of various forms and sizes, and are adapted to the architecture of the little altar, and to its various parts. Many of them have now perished, though several are yet in existence, the smallest of which chiefly represent histories from scripture, and the largest of them the acts of the Evangelists, to the number of fourteen, and about one-sixth of a braccio (an arm, two-thirds of a yard) in height.] [Footnote 95: Pace, a sort of sacred vessel borne in procession by the priests; literally, it means peace.] [Footnote 96: In this edition I ought to mention another zolfo (a sulphur cast) of the same pace of S. Giovanni, in possession of his excellency the Senator Prior Seratti. This, when compared with the model, corresponds line for line; there is a full display of the very difficult character of Maso's heads, and what is still more decisive, is, that it is cut, or indented, an effect that must have been produced according to the manner already described. The zolfo Durazzo, as appears from the impression, does not correspond so well; some of the flowers and ornaments of drapery are wanting; it is not equally finished, and it seems smooth on the surface. This does not derogate from its genuineness, for as several proofs were taken of the same _pace_, which was cut by degrees, if we find less completeness in the Durazzo proof, it is only an indication of its having been taken before the rest. And if the impressions of the cuts are not so plainly traced as in the other, I do not, therefore, conjecture that they do not exist. The zolfi of the fathers of Camaldoli already cited, seem as if they were printed, and smooth. A fragment breaking off, highly polished on the surface, the cuts were then discovered, even to the minutest lines, as many professors, even the most experienced in the art of printing, to their surprise, have witnessed; and they conjectured that the ocular illusion might arise, 1st, from the fineness of cut made with the style, or possibly with the graver, which was diminished in proportion as it passed from the sheet to the earthen mould, and from this to the zolfo; 2d, from the density of the ink, when hardened between the cuts or hollows of the zolfo; 3d, from a coat of bluish colour laid on the work, of which there remain traces, and from that which time produces both in paintings and on cards. I have not a doubt, that, if the experiment were tried on the Durazzo zolfo, the result would appear exactly the same. The extrinsic proofs of its origin, also adduced by Gori, together with