The Humours and the Dyes

This contribution presents the edition and translation of a new manuscript witness to the Arabic tradition of Galenic summaries On urine (Ms Collegesville, Minnesota HMML OLM ooo41). Uroscopy appears to be a complementary diagnostic element in ancient medicine, which gained increasing popularity in later centuries, as attested by the rich traditions in Greek and Arabic. The summary, as attested in this manuscript witness, compares the four bodily humours to dyes, creating a concrete and tangible frame for the study and memorization of this diagnostic branch. This text, moreover, stresses the performative dimension of uroscopy, particularly in the form of instruc-tions for physicians on how to recognize devious fake samples offered by obnoxious people seeking to test the physician in order to undermine his authority and credibility.