Inscribed "Henri Garnier photographie inalterable". This is a very early, unique carbon print possibly submitted by Garnier for the Duc de Luyne ‘small’ prize of permanency. Garnier took second but was listed under Garnier and Solomon. It is perhaps among the first ‘permanent’ photographic prints ever made.
D’encre Et De Charbon: Le Concours Photographique Du Duc De Luynes 1856-1867. Paris: BibliotheÌque nationale, 1994
Marbot, Bernard. After Daguerre: Masterworks of French Photography (1848-1900) from the Bibliothèque Nationale. New York: Metropolitan Museum of Art, in association with Berger-Levrault, Paris, 1980. P. 72
Hanson, David Checklist of photomechanical processes and printing 1825-1910, 2017 p. 55
British Journal of Photography: https://www.google.com/books/edition/The_British_Journal_of_Photography/dlA7AAAAMAAJ?hl=en&gbpv=1&bsq=Garnier June 12, 1874 p. 283