“These tests mark the Earliest known experiments in photolithography – an important original photomechanical process, whose developments paved the way to the dissemination of photography in print.” 
As early as 1848 Lemercier began experimenting with technology that could possibly unite photography and lithography. Consulting with the optician Noël Paymal Lerebours and chemists Charles-Louis Barreswil and Louis-Alphonse Davanne, Lemercier was the first to attempt to transform the fugitive paper-based photograph into a permanent ink-based photolithographic print. He named his process Lithophotographie.
By mid-1852 the team had succeeded in executing experimental trial proofs which he labled Essais de Lithophotographie; Impression Obtenue directement sur Pierre par la Photographie and, on June 28, delivered them along with an explanation of the process to the Académie des Sciences seeking a patent. On August 16, François Arago presented the work and the patent was granted.
Two years later, Lemercier went further and published a set of six halftone prints under the title Lithophotographie: Ou Impressions Obtenues Sur Pierre À L’aide De La Photographie. A full set of these prints was given to the Paris Academy of Sciences (9 January, 1854) as further proof that practical photo-lithography had been achieved. However, the success of their method was limited. Lemercier soon abandoned it because only a few copies could be reliably made and after 1860 he adopted Alphonse Poitevin’s process in preference to the method he and his associates had patented. 
Stamped with, "Breveté S. G. D. G". Breveté SGDG was a French type of patent that ceased to exist in 1968. The name was a common abbreviation for "Breveté Sans Garantie Du Gouvernement“ (patent without government guarantees).
Getty Object Number: 84.XP.779.5
 La Photographie II Collection Marie-Thérese et André Jammes Paris 21 March 2002 p. 54
 Jeff Rosen (1987) The Printed Photograph and the Logic of Progress in Nineteenth-Century France, Art Journal, 46:4, 305-311, DOI: 10.1080/00043249.1987.10792378