[Alcaloids discovery, markers for the history of organic chemistry].

The development of organic chemistry is well fitted by the history of dyes. Are alkaloids as good markers? In 1876, Chevreul distinguished two steps in the history of these organic alkalis. The first began with Derosne who analyzed opium in 1803, followed by Seguin and mainly Sertuerner. It was closed about 1820 with Pelletier and Caventou researches, including works of Robiquet and Gomes from Lisbon. Next years, chemists investigated properties and chemical structures. With Pasteur, alkaloids participated to the emergence of stereochemistry, and with Claude Bernard, to the birth of a new science, physiology. Chevreul could not anticipate success of organic synthesis which blooms during the XXth century.