PREFACE.

The three treatises contained in the volume.

With the exception of one short treatise in the Appendix,¹ the works of Roger Bacon contained in this volume have now for the first time been given to the world. They consist of:—

The Opus Tertium has already been partially known to the biographers of Bacon by the extracts made from it at different times; still more recently by the copious description of its contents published in the “Journal des Savants” for 1848 by Victor Cousin. The Opus Minus has attracted little or no notice, notwithstanding a remarkable quotation from its contents given by Dr. Hody in De Bibliorum Textibus. This neglect is attributable, perhaps, to an erroneous notion which has long prevailed as to its nature and contents. The account given of it by Dr. Jebb, in his preface to the Opus Majus, has tended to lead the admirers of Roger Bacon still further astray. From the work as now published, it will be seen that Dr. Jebb has confounded it with other writings of Bacon and has formed an imaginary notion of its contents. Of the third treatise, which I have ventured...

¹ De Nullitate Magiae; now first collated with the Sloane MS.