He was interested to economic plants, especially rubber. He accepted the proposal of the Congolese government to organize the first purely botanical exploration in the Independent Congo State. During the second year of this expedition, he died of malaria (27 February 1897, in Luébo Station). The large Congo collection, obtained during this two years, was donated by the Independent Congo State to the Garden where it has been studied by Durand and De Wildeman. Due to his death, the collection was hardly labelled, however. His itinary has been reconstructed by Liben (Bull. Jard. Bot. Etat Brux. 35: 375-388). Subsequent to this publication, his field notes have been rediscovered and were used to provide his specimens with complete labels.