Interpreter of the king, Pétis de la Croix had the occasion, in 1697, to inquire from a small tripolitan delegation (which was composed of three governmental officials and two black slaves) about commercial exchanges between Tripoli and different countries in the interior of Africa. The information obtained was recorded by the author and his notes still exist in their original form. Dealing with the organisation of caravans, the journeys covered and above ail with the goods exchanged these notes also contain precious information in what concerns prices and, to some extent, quantities of the main products brought from the deep interior of Africa : gold, slaves, tusks, senna and tin. Or great importance for the transaharan commercial history ...