We are to attribute to Maso, says Vasari, "the beginning of engraving upon copper," an art, which for the sake of greater perspicuity, I shall distinguish into three different states; the first of which will be found as follows. Finiguerra was in the habit of never filling the little hollows or cuts prepared in the silver plate until he had first made proof of his work. "For this purpose, as in taking a cast, he impressed them with earth, upon the top of which having thrown a quantity of liquid sulphur, they became imprinted, and filled with smoke; which, with the aid of oil, gave him the effect of the work in silver. He also produced the same with moistened paper, and with the same tint or ink, pressing it sufficiently hard with a round roller, with a smooth surface throughout. This gave them not only the effect of being printed, but that of having been designed with ink."[93] So far we quote Vasari in the preface to his Life of Marc Antonio. He adds, that in this plan Finiguerra was followed by Baldini, a Florentine goldsmith; next to whom he mentions Botticelli; and he might have added the name of Pollaiuolo. Finally, he concludes that the invention was communicated from Florence to Mantegna at Rome, and to Martino, called De Clef, in Flanders. These proofs, the first of their kind, made by Finiguerra, have, for the most part, perished. Some, which are attributed to him, in possession of the fathers of Camaldoli, are not ascertained to be his.[94] We are assured, however, that the sulphur of the pace[95] cut for S. Giovanni in 1452, upon which he represented the Assumption of our Lady, in a variety of minute figures, is from his hand. It was formerly in the museum of the Proposto Gori, who gave a description of it in his Dittici (a treatise upon a peculiar kind of altar-pieces, tom. iii. p. 315), and it is now in the Durazzo cabinet, with a memorandum in Gori's own hand, in which he declares that he had compared it with the original.[96] Of the proofs made on paper none are ascertained to exist, with the exception of that of the Assumption recognized by the Ab. Zani, in the national collection at Paris. It was made known by him in the year 1803; and to this I may add the Epiphany, in an inferior style, but more exactly finished, which I found in the possession of the Senator Martelli, besides a duplicate belonging to S. E. Seratti. It appears from its style, the work of Finiguerra, and to have been executed before the Assumption. It is doubtful whether specimens exist in the ducal gallery, a question which I leave to the solution of abler pens than mine. We have in the Durazzo collection, the proofs or models of many silversmiths, whose names are unknown; and for many more we are indebted to Sig. Antonio Armanno, an excellent connoisseur in prints, to whom I shall have occasion to recur more than once. Following the ideas thrown out by Vasari in the passage cited, he concluded that these impressions