It is certain that Irenæus was bishop of Lyons, in France, during the latter quarter of the second century. The exact period or circumstances of his ordination cannot be determ- ined. Eusebius states (Hist. Eccl., v. 4) that he was, while yet a presbyter, sent with a letter, from certain members of the Church of Lyons awaiting martyrdom, to Eleutherus, bishop of Rome; and that (v. 5) he succeeded Pothinus as bishop of Lyons, probably about a.d. 177. His great work Against Heresies was, we learn, written during the episcopate of Eleutherus, that is, between a.d. 182 and a.d. 188, for Victor succeeded to the bishopric of Rome in a.d. 189. This new bishop of Rome took very harsh measures for enforcing uniformity throughout the Church as to the observance of the paschal solemnities. On account of the severity thus evinced, Irenæus addressed to him a letter (only a fragment of which remains), warning him that if he persisted in the course on which he had entered, the effect would be to rend the Catholic Church in pieces. This letter had the desired result; and the question was more temperately debated, until finally settled by the Council of Nice. The full title of the principal work of Irenæus, as given by Eusebius (Hist. Eccl., v. 7), 313 and indicated frequently by the author himself, was A Refutation and Subversion of Know- ledge falsely so called, but it is generally referred to under the shorter title, Against Heresies. Several other smaller treatises are ascribed to Irenæus; viz., An Epistle to Florinus, of which a small fragment has been preserved by Eusebius; a treatise On the Valentinian Ogdoad; a work called forth by the paschal controversy, entitled On Schism, and another On Science; all of which that remain will be found in our next volume of his writings. Irenæus is supposed to have died about a.d. 202; but there is probably no real ground for the statement of Jerome, repeated by subsequent writers, that he suffered martyrdom, since neither Tertullian nor Eusebius, nor other early authorities, make any mention of such a fact. As has been already stated, the first printed copy of our author was given to the world by Erasmus. This was in the year 1526. Between that date and 1571, a number of reprints were produced in both folio and octavo. All these contained merely the ancient barbarous Latin version, and were deficient towards the end by five entire chapters. These latter were supplied by the edition of Feuardent, Professor of Divinity at Paris, which was published in 1575, and went through six subsequent editions. Previously to this, however, another had been set forth by Gallasius, a minister of Geneva, which contained the first portions of the Greek text from Epiphanius. Then, in 1702, came the edition of Grabe, a learned Prussian, who had settled in England. It was published at Oxford, and contained considerable additions to the Greek text, with fragments. Ten years after this there appeared the important Paris edition by the Benedictine monk Massuet. This was reprinted at Venice in the year 1724, in two thin folio volumes, and again at Paris in a large octavo, by the Abbé Migne, in 1857. A German edition was published by Stieren in 1853. In the year 1857 there was also brought out a Cambridge edition, by the Rev. Wigan Harvey, in two octavo volumes. The two prin- cipal features of this edition are: the additions which have been made to the Greek text from 839 Introductory Note to Irenæus Against Heresies