On Rules Regarding the Practical Part of the Medical Art was lost to scholars for centuries before it was discovered in the Biblioteca Nacional de Espana by the great bio-bibliographer Moritz Steinschneider, who initially thought it was simply another copy of On Asthma. The publication of this new translation marks the first time the Arabic manuscript and Gerrit Bos’s English version have been available to a modern audience in any form. It is in Maimonides’s favored aphoristic format and contains some unique advice on serious abdominal wounds, which is most likely a reflection on Maimonides’s own experience with battlefield casualties.