DUCHESNE (Jean). Essay on Nielles: Engravings by 15th-Century Florentine Goldsmiths. Paris: Merlin, 1826. — In-8, 212 x 139: (2 ff.), xij, 381 pp., 8 plates, printed cover. Dark brown half-maroquin, decorated ribbed spine, gilt head, untrimmed, cover preserved (20th-century binding). Very rare first edition. Jean Duchesne, known as “Duchesne the Elder ” (1779–1855), an art writer and historian of engraving associated with the Print Room of the Royal Library, conceived this essay as a supplement to Bartsch’s *Peintre-Graveur* (21 volumes), filling the gap regarding niello. This is the very first work devoted to this technique—that is, to the trial prints of engravings by 15th-century Florentine goldsmiths—documenting the discovery of the art of printing metal engravings. The book catalogs all the nielles known at the time, cabinet by cabinet—the King’s Library, the Durazzo collection in Genoa, the Woodburn, Sykes, and Stowe collections in England, the Trivulcio and Malaspina collections in Milan, the Florence Gallery, the Institute of Bologna—with each entry providing the dimensions, the nature of the piece (silver, sulfur, or paper), and its location. Pieces known only by description are marked with an asterisk, and questionable attributions are listed at the end of the volume, designated by letters. The classification is systematic: nielles arranged by material and numbered consecutively, with series that are now scattered having been reconstructed, followed by final tables organized by silversmith-nieller and by collection, plus a general alphabetical table. The edition is illustrated with 8 plates: two facsimiles lithographed by Charles Girardet, a niello lithographed by Smith, the plate of the Pax de Finiguerra, three plates based on English nielles, and the portrait of Abbé Zani, to whom we owe the discovery that establishes the date of the origin of metal printing. A fine copy bound in a paperback-style binding. Spine slightly faded. Foxing.