Albumen-coated paper trial print for the heliogravures of the Duc de Luynes, Voyage D’Exploration a La Mer Morte from the family archive and Charles Negre’s personal album.
The term “Pommier de Sodome” (Apple Tree of Sodom) seems to refer to a sentence Flavius Josephe wrote in the work “Bellum Judaiscum”, which evokes the fruit growing in the territory of the ancient Sodom: When they look ripe and are plucked, they are reduced to smoke and ashes in the hand. The tree is toxic in all its parts, especially its latex.
During the day, M. Vignes went to take a photograph of the fountain at Ain Djidy, with the fine apple-tree of Sodom in vegetation next to it, and intended after that to take an overall view of the valley. Unfortunately, the glass plates had not been correctly prepared in Paris, and only took a single acceptable picture, that of the plant near the spring. The others did not come out under the action of the developing solution’. 
 Philip Foliot, “Louis Vignes and Henry Sauvaire: Photographers of the Expedition of the Duc de Luynes,” History of Photography 14, no. 3 (1990): 235-236.