[Possibilities and limits of early photography in dermatology. The "Clinique photographique de l'hôpital Saint-Louis" von 1868].

Photographic images are an intrinsic part of modern dermatology, essential for documentation, publication and teaching. Although there were no strong technical obstacles to prevent the use of black and white photographs in the atlases of the late 19th century, famous works such as Kaposi's "Handatlas der Hautkrankheiten" still utilized hand-colored copper etchings for illustration. Nevertheless, M.A. Hardy and M.A. de Montméja made an effort to introduce photography into dermatology as early as 1868. In their "Clinique photographique de l'hôpital Saint-Louis" of 1868 we find a variety of dermatological diseases, discussed and illustrated with 50 black and white photographs. The majority of these pictures were then modified with hand coloring in various shades of intensity. The authors insisted on this technique to assure the diagnostic value of the pictures. Besides an extensive review of the Atlas, we discuss the limits and perspectives of early photographic images in the "Clinique photographique" compared to the detailed hand-colored copper etchings of that time, as well as to modern color photographs.