MAUVAIS VICTOR : (1809-1854) French Astronomer and Politician. Mauvais won the Lalande Prize in 1843 for the discovery of comet C/1843. He is credited with several more comet discoveries. Mauvais committed suicide at the age of 45, leaving unfinished an important work on the determination of the positions of the most important stars. Rare and very important A.L.S., `V. Mauvais´, one page, 4to, Paris, 9th July 1844, to Monsieur De Vico, an Italian colleague, Astronomer, and Director of the Observatory of the Roman College, in French. To the heading, Mauvais writes from `Observatoire de Paris´, and reports to his correspondent about his very important and recent discovery, stating in part `J´ai l´honneur de vous annoncer que dans la nuit de Dimanche à Lundi dernier j´ai découvert une comète dans la constellation d´Hercule´ (`I have the honour to announce to you that during the night of last Sunday to Monday I discovered a comet in the constellation of Hercules..´ Mauvais further lists his observations and positions, with numbers and degrees, and underlining `En composant ces deux positions on conclut le mouvement Diurne suivant..´ (`By composing these two positions we conclude the following Diurnal movement…´) He further again adds some doubts on one of his conclusions and explains why. A letter of extremely interesting astronomy content. With address leaf bearing two postmarks. G to VG