Examiner at Polytechnique in 1813, Dulong did in 1820 with Berzélius the analysis of water. Professor of physics from 1820 to 1829 and director of studies at Polytechnique from 1830 to 1838, he was elected (for his memoir on the laws of cooling written with Petit) from 1823 to the Institute (general physics section), which he presides in 1828.