MÉMOIRE SUR UNE APPARENCE DOUTEUSE DE MIRAGE, par Le Professeur P. (PIERRE) PREVOST. La Société de Physique et d'Histoire Naturelle, Geneva, 1834. Pagination: (2), 18 pages. printed on rag paper that remains bright white, 4to., 8.5x10.75 inches (21.5x27 cm). There is one plate at the rear, 8x5.75 inches ( 21x14 cm) that contains two figures. Bound in recent plain brown paper wrappers. VERY GOOD condition. Many pages are untrimmed / unopened at their top edge; there is light foxing, some corner creases, overall bright, clean, clear and unmarked. The recent plain brown paper wrappers have creases and some soiling. Rare booklet of Pierre Prévost (1751-1839), physicist and philosopher of Geneva, recognized in the field of science for his contribution to the theory of heat exchange (he explained Pictet's experiment by arguing that all bodies radiate heat, no matter how hot or cold they are). He was also a renowned Hellenist, who, among other things, contributed a translation of Euripides. Early on he held the chair of literature at the University of Geneva. In 1786 he became politically active and was a member of the Council of Two Hundred. In 1793 he was appointed to the Chair of Philosophy and General Physics at the University of Geneva, a position he held until 1823. In this booklet, MÉMOIRE SUR UNE APPARENCE DOUTEUSE DE MIRAGE, Prévost explains the scientific causes for visual appearances that seem real but are not (i.e. mirages). It is known that Prévost

himself suffered from mirages, which he considered a type of visual affectation.