The record of the Index is also to be considered as an important contribution to the history of literature. Thomas James, whose treatise on the _Index Generalis Librorum Prohibitorum_ was printed at Oxford in 1627, says in his preface that his book is addressed particularly to the curators of the Bodleian Library to whom it should serve as a guide concerning the works which it was particularly desirable to collect and to preserve; only the curators must be sure to secure the earlier and, therefore, unexpurgated editions. Bishop Barlow writes that he has found the “_Indices Expurgatorii_ invaluable as records of the literature of the doctrines and opinions obnoxious to Rome.... Their _Indices Expurgatorii_ are very good common-place books and repertories (for that use we make of them) by help of which we may presently find what any author by them censured has uttered against the vulnerable parts of the Catholic system. In these _Indices_ we are directed to the book, chapter, and line where anything is spoken against any superstition or error of Rome; so that he who has the _Indices_ cannot want testimonies against Rome.”[2] Reusch points out that the Indexes have preserved the record and the purport of not a few works of interest and importance, the very existence of which would otherwise have been lost sight of. It is also the case that the Index lists have preserved the titles of a number of works of comparatively trivial importance, which, if they had not been fortunate enough to secure the condemnation of the Church, would have fallen still-born from the press. It was the practice, in making condemnation of books either through a general Index or under a separate decree, to order destroyed such copies of the condemned books as could be collected, and this destruction was, as a rule, done by fire. In the record of censorship, there are, however, a number of instances of books which had received the honour of a special condemnation for burning, the titles of which had not appeared in any Index issued by the Church or in any separate papal or diocesan decree. The books so recorded were, with hardly an exception, condemned under civil authority. The writers who have brought together records of books condemned to be burned (of whom Peignot is perhaps the most important) give, under the same general heading, titles of books selected from the Index, books condemned under special decrees of the Church, and works which had fallen under the censorship of the civil authorities. As will be noticed in the later chapters, the special emphasis given to the importance of a book through the burning of copies in a public place, constituted a valuable advertisement and usually extended its influence.