CRL owns sections IV (law) and V (medical & natural sciences). Section IV contains the Decretals of Gregory IX and of Gratian, Justinian's Works, as well as the works of many Popes (Innocent IV, Boniface VIII etc.). Section V includes such works from the Christ Church collection as the Lectio Astronomica (1703) and a 17th-century Euclides Elementum. Those from New College include works by Hippocrates, Pliny, Ptolemy, Aristos, Galen, Averroes, and Roger Bacon.