Marc François Louis Secrétan (1804 - 1867), born in Lausanne, professor of mathematics at the Academy of Lausanne, moved to Paris in 1844. In 1845, he joined Lerebours and the firm "Lerebours et Sécrétan" used that name until 1880's and beyond. Sécrétan became head of Lerebours et Sécrétan after 1855.