In 1835 the French Academy sent Antoine on a scientific mission to Brazil, the results being published at a later date (1873) under the title of "Observations relatives à la physique du globe faites au Brésil et en Éthiopie". In 1837, the two brothers started for Ethiopia, landing at Massawa in February 1838. They journeyed throughout Ethiopia, travelling as far south as the Kingdom of Kaffa, sometimes together and sometimes separately. In addition to his studies in the sciences, he delved into the political fray exerting influence in favour of France and the Catholic missionaries. The two brothers returned to France in 1848 with notes on the geography, geology, archaeology, and natural history of the region.