London: T. & R. Willats, 1850. First English language edition. 16mo., v, -24 pp.,  pp. Quarter morocco and cloth with morocco tips, titled in gilt on spine; the original printed wrappers are bound-in Gentle crease to the corner of the text. A very good copy. Item #26108
Expanded English translation of Le Gray's original manual TRAITÉ PRATIQUE DE PHOTOGRAPHIE SUR PAPIER ET SUR VERRE. The inventor introduced gold toning of prints, which he describes here. He also describes gelatin coatings for negatives and their processing, as well as printing them. Perhaps the very earliest use of these coatings for negatives.
WorldCat locates copies at: Williams College, University of Minnesota, University of Texas - Hary Ransom Center, British Library, Imperial College London, and the Metropolitan Museum of Art. Gernsheim, Incunabula No. 690. Roosens and Salu No. 5966.