On May 10th 1952 I acquired after long and patient investigations a coptic codex, which contains the following writings: 1. An Apokryphon of James, the brother of the Lord, dealing with secret doctrines revealed by Jesus after his resurrection; 2. The Gospel of Truth, which is to be identified with the Veritatis Evangelium mentioned by Irenaeus, Adversus Haereses III, 11, 9; this esoteric text, which was intended to be a sort of fifth gospel and is in fact the only heretical gospel known up till now, is undoubtedly of valentinian origin and probably goes back to the middle of the second century; 3. A Letter to Rheginos on the Resurrection, a short valentinian treatise strongly influenced by Pauline and Johannine theology, on the gnostic conception of spiritual resurrection; this dissertation gives us an impression of the heretical views on sacramental death and rebirth, which were so severely criticised by several Fathers of the Church, especially by Tertullian In his work de Resurrectione Mortuorum ; 4. A long and systematic exposition of valentinian theology, which may help us to appreciate more fully the relations between the ,,falsely so called Gnosis of the valentinian heresy and the ,,true Gnosis of Clement of Alexandria and Origenes. The teaching of this treatise, whose title is lost, shows rather strong affinity with the doctrine of Heracleon, the pupil of Valentinus, who wrote a commentary on the Gospel of John.