[From simple past to future tense. The essential role of medical history, an example: saturnism].

Too frequently seen as an underknowledge, History of Sciences and Medicine may be quite on the contrary see understood as anmatter exemplary matter of instruction for students and practicians. This paper shows how it is possible to interpret difficult cases by a good knowledge of very old medical and historical stories, and the example of past diseases owing to saturnism (lead poisoning) may be very eloquent.