[History of a discovery: Ibn al-Nafās and the lung circulation].

The discovery of a copy of a text, with the title Commentary on the anatomy of the Canon, allows the attribution of the description of lung circulation to Ibn al-Nafīs, which is the author of this work. It was common opinion that this discovery had not a special echo and the new discovery of the little circulation in XVIth century was independent from the one in XIIIth century. Also if it is not still possible to specify the exact itinerary of this discovery, we have reason to think that the work of Ibn al-Nafīs was the primary source of the rediscovery of the lung circulation in XVIth century.