The discovery of quinine, 1820. Oil painting by Ernest Board, 191-.

Pierre-Joseph Pelletier is shown standing facing the viewer, while Joseph-Bienaim Caventou sits with his back to the viewer so that we do not see his face. This composition was chosen because the portraits of Pelletier show him as a young man, though he was the older of the two, and the portraits of Caventou show him as an old man, though he was seven years younger than Pelletier. Not having any reference sources to show Caventou as a young man, Board has resorted to showing him from behind, as if the viewer were just dropping in on the laboratory, and Caventou had not heard us arriving.