The two books which followed the _Expositio_ are a Latin translation of the _Nicomachean Ethics_ of Aristotle by Leonardus Brunus Aretinus, and a treatise on original sin by Ægidius de Columna. The first, a quarto of one hundred and seventy-four leaves, is dated 1479, but no month is mentioned. By this date the printer had discovered which way up a capital Q should stand, and we find it always correctly printed, though some minor mistakes of the _Expositio_ are continued, such as using a broken lower-case h sometimes for a b and sometimes, upside down, for a q. The general printing of the book was however improved, and the lines more evenly spaced out to the right-hand edge. The second book, the treatise of Ægidius, _De peccato originali_, is dated March 14, 1479, but this date may be taken as 1479-80. In this book we find red printing introduced for the first and last time in an Oxford book. It is by far the rarest of the early Oxford books, perhaps on account of its small size, for it contains only twenty-four leaves, and the three copies known were all bound up in volumes with other tracts. The Bodleian copy belonged to Robert Burton and came to the library with his books; that in Oriel College Library was in a volume with the _Expositio_ and some foreign printed quartos, which, though kept together, was rebound in the eighteenth century. The third copy, now in the Rylands Library at Manchester, was, until about thirty years ago, in a volume with the _Expositio_ and three foreign printed tracts, including an edition of Michael de Hungaria’s _Tredecim sermones_, a book which has at the end a curious sermon containing a notice of the ceremony of incepting in theology at Oxford and Cambridge, with a few sentences in English. The volume had belonged to a certain A. Hylton in the fifteenth century, and was in its original stamped binding, a very fine specimen of contemporary Oxford work. The volume was sold in an auction about 1883, and the purchaser ruthlessly split up the volume and disposed of the contents. The two Oxford books found their way into Mr Quaritch’s hands, who sold the _Expositio_ to an American collector, while the Ægidius was bought by Lord Spencer to add to the fine series of Oxford books at Althorp. These first three Oxford books form a perfectly distinct group. In them but one fount of type is used, and they are without any kind of ornament. It is, however, quite impossible to suppose that an interval of eleven years separated the printing of the first and second books. The press-work of the second shows a slight improvement on the first, but only what the experience gained in printing a first book would enable the printer to carry out on a second attempt.