A.-P. Martial (Adolphe-Martial Potémont) (1827-1883) Letter on the elements of etching. 1864. Complete suite of 4 etched plates [305 x 455]. Beautiful proofs on laid paper. A few small light spots. Slight dusting and minor accidents to the edges of the leaves. Filled buff vellum cover, illustrated with an engraving on the upper cover, dusty and faded (accidents and tears at the edges). Rare: "Few institutions possess the complete series; the Art Institute of Chicago (inv. 1949.653a-e); the Minneapolis Institute of Art (inv. P.3,234.1-5); the British Museum in London (inv. 1865,0429.137-141); the Rijksmuseum in Amsterdam (inv. RP-P-1950-155A-E)" (Fondation Custodia, online notice).