In 1821 he proposed to the Tsar Alexander I and to the Academy of Sciences to lead an ambitious exploratory and scientific expedition from São Paulo to Pará, in the Amazon, via a fluvial route. In March 1822, he returned to Rio in the company of scientists Édouard Ménétries, Ludwig Riedel, Christian Hasse and Nester Gaverilovitch Rubtsov, who would take care of zoological, botanical, astronomical and cartographical observations during the expedition. With the aim of illustrating and documenting his findings, the Baron hired painters Hércules Florence, Johann Moritz Rugendas and Adrien Taunay. The inventor of the bicycle Karl von Drais was also a participant in the expedition. After extensive preparations, the Langsdorff Expedition departed with 40 people and 7 boats from Porto Feliz, by the Tietê river on 22 June 1826 and reached Cuiabá, in Mato Grosso on 30 January 1827. The expedition was then divided into two groups: the first one, with Langsdorff and Florence, was able to reach Santarém on the Amazon River on 1 July 1828, with enormous difficulties and suffering. Most of the members of the expedition became ill with tropical fevers, including the Baron de Langsdorff. As a consequence of the febrile attacks, he became insane at the Juruena River in May 1828. Adrien Taunay died by drowning in the Guaporé River and Rugendas abandoned the expedition before its fluvial phase. Therefore, only Florence remained during the whole expedition. The expedition was joined again in Belém and returned by ship to Rio de Janeiro, arriving on 13 March 1829, almost three years and 6,000 km after its departure. Huge scientific collections were deposited into Kunstkamera and later formed basis for South American collections of Russian museums. However, the rich scientific records of the expedition, comprising many descriptions and discoveries in zoology, botany, mineralogy, medicine, linguistics and ethnography, that were sent to Saint Petersburg by the expedition, were not published and were lost in the archives for a century. They were found again by Soviet researchers in funds of the USSR Academy of Sciences archive in 1930. Due to the travel's hardships, Langsdorff team was unable to collect many biological specimens or study them in detail, so most of their account is geographic and ethnographic, being particularly interesting on the many indigenous people of Brazil they met, many of which became extinct. Today, a large part of the material has been recovered and is in the Ethographic Museum, the Zoological Museum and in the repositories of the Academy of Sciences of St. Petersburg. Langsdorff returned to Europe shortly thereafter, in 1830, and died in Freiburg, Germany, of typhus, in 1852. A species of venomous South American coral snake, Micrurus langsdorffi, is named in his honor.
Media
A film documentary, featuring Adriana Florence, a grand-grand-granddaughter of Hércules Florence living in Campinas, Brazil, has been made by the Discovery Channel and retraces part of the expedition's itinerary. It also visited St. Petersburg's Langsdorff museum collections. The director was Mauricio Dias.
