Cet article comprend l’étude et l’édition du Versus de historia euangelica, un poème anonyme de 288 hexamètres léonins, qui relate l’histoire de la naissance du Christ, de son ministère et de sa crucifixion. En raison de la nature contradictoire et répétitive des récits évangéliques, le poète suit l’organisation du matériel biblique de l’ Historia scholastica de Pierre le Mangeur, dont l’achèvement en 1173 constitue le terminus post quem de la composition du poème. On peut appeler le style du Versus épigrammatique. (...) En fait, le poème dans son entier se lit comme une collection de brefs tituli indépendants qui pourraient être sortis de leur contexte et utilisés comme légendes pour des représentations figuratives appropriées. (shrink)

This article presents a study and a critical edition of the short anonymous treatise on the rainbow starting with the incipit Inter omnes impressiones. The text was known to Nicole Oresme who engages with it twice: in his Questiones in Meteorologica de prima lectura and in Le livre du ciel et du monde. This Tractatus de iride, previously unknown to scholars, is transmitted in three late thirteenth-century manuscripts. It uses Robert Grosseteste’s theories of the rainbow as caused by the refraction (...) of sunlight and of colour as light incorporated in aereal particles. However, contrary to Grosseteste, the Tractatus de iride adopts the idea of different degrees of incorporation of light, which is also found in the scientific writings by Adam of Exeter, a Franciscan scholar belonging to the same Oxonian circle as Grosseteste. Moreover, the Tractatus de iride develops original propositions in regard to the role of individual raindrops, the importance of the angle from which the rainbow is observed, and the idea of the spirituality of the colours in the medium, which were central also for Roger Bacon’s and Nicole Oresme’s own theories of the rainbow. (shrink)