[The role of medicine in a lawsuit on the adulteration of tobacco under the old regime (Burgos 1667)].

This article studies a court case on the adulteration of tobacco in Burgos in 1667. The expert work done by physicians and apothecaries throughout this trial plays a central role. The evolution of this judicial process is described in detail, and additional information is provided on the organisation of the tobacconist's, the preparation of tobaccos, the spectres associated with the adulteration of tobacco and the administration of justice under the old regime. In a second phase, the "experiences" performed by professionals and the methods of analysis on which their ideas are based are studied, relating the irregular scientific performance to the position occupied in the field of health professionals in Burgos at that time. Finally, based on what has been observed, speculations are made on the shift in control of the adulteration, from the municipal ambit in the early Middle Ages to its integration into the Crown institutions and its relationship with the promotion of physicians and pharmacists as experts in the subject.