In his Homily on Psalm 138, § 4, Hilary briefly mentions the Patriarchs as examples of faith and adds, ‘but these are matters of which we must discourse more suitably and fully in their proper place.’ This is a promise to which till of late no known work of our writer corresponded. Jerome had, indeed, informed us Vir. Ill. 100. that Hilary had composed a treatise entitled De Mysteriis, but no one had connected it with his words in the Homily. It had been supposed that the lost treatise dealt with the sacraments, in spite of the facts that it is Hilary’s custom to speak of types as ‘mysteries,’ and that the sacraments are a theme upon which he never dwells. But in 1887 a great portion of Hilary’s actual treatise on the Mysteries was recovered in the same manuscript which contained the more famous Pilgrimage to the Holy Places of Silvia of Aquitaine J. F. Gamurrini, S. Hilarii Tractatus de Mysteriis et Hymni, etc., 4to., Rome, 1887. The De Mysteriis occupies pp. 3–28.. It is a short treatise of two books, unhappily mutilated at the beginning, in the middle and near the end, though the peroration has survived. The title is lost, but there is no reason to doubt that Jerome was nearly right in calling it a tractatus, though he would have done better had he used the plural. It is written in the same easy style as the Homilies on the Psalms, and if it was not originally delivered as two homilies, as is probable, it must be a condensation of several discourses into a more compact form. The first book deals with the Patriarchs, the second with the Prophets, regarded as types of Christ. The whole is written from the point of view with which Hilary’s other writings have made us familiar. Every deed recorded in Scripture proclaims or typifies or proves the advent of the incarnate Christ, and it is Hilary’s purpose to display the whole of His work as reflected in the Old Testament, like an image in a mirror. He begins with Adam and goes on to Moses, deriving lessons from the lives of all the chief characters, often with an exercise of great ingenuity. For instance, in the history of the Fall Eve is the Church, which is sinful but shall be saved through bearing children in Baptism Ed. Gamurrini, p. 5.; the burning bush is a type of the endurance of the Church, of which St. Paul speaks in 2 Cor. iv. 8 Ib. p. 17.; the manna was found in the morning, the time of Christ’s Resurrection and therefore of the reception of heavenly food in the Eucharist. They who collect too much are heretics with their excess of argument Ib. p. 21; there is the not uncommon play on the two senses of colligere.. In the second book we have a fragmentary and desultory treatment of incidents in the lives of the Prophets, which Hilary ends by saying that in all the events which he has recorded we recognise ‘God the Father and God the Son, and God the Son from God the Father, Jesus Christ, God and Man Ib. p. 27..’ The peroration, in fact, reads like a summary of the argument of the De Trinitate. Of the genuineness of the little work there can be no doubt. Its language, its plan, its arguments are unmistakably those of Hilary It must be confessed that some authorities refuse to regard this work as the De Mysteriis of Hilary. Among these is Ebert, Litteratur des Mittelalters, p. 142, who admits that the matter might be Hilary’s, but denies that the manner and style are his.. The homilies were probably delivered soon after he had finished his course on the Psalms, of which they contain some reminiscences, such as we saw are found in the later Homilies on the Psalms of earlier passages in the same. In all probability the subject matter of the De Mysteriis is mainly drawn from Origen. It is too short, and too much akin to Hilary’s more important writings, to cast much light upon his modes of thought. He has, indeed, no occasion to speak here upon the points on which his teaching is most original and characteristic.