from 1815 to 1820, he studied medicine at the university of paris. roulin visited colombia from 1822 to 1828, becoming an expert on the natural history of the country. in 1824 he served as a scientist on an expedition funded by the colombian government to survey the meta river, a tributary of the orinoco river. in colombia, he also inspected the gold mines at la vega de supía y marmato, and traveled the magdalena river. in addition, while in south america, he visited venezuela, peru and ecuador.