tain 3883 distinct tracts; and, in the Miscellaneous portion, 173 volumes contain 1402 tracts. Thus 765 volumes of the above total of 20,018 volumes, comprise as many as 5285 separate works.
The Library contains, besides, a valuable collection of Oriental Manuscripts, especially Sanscrit, formed by Sir William Jones during his residence in the East, and presented to the Society, after his de- cease, by Lady Jones. Many of these are unique in Europe ; and their value is attested by learned foreigners coming to this country for the express purpose of consulting them. Of the Miscellaneous Manuscripts, the autograph of the Principia, presented by Sir Isaac Newton to the Society, and from which the first edition was printed, must be considered invaluable. An unpublished MS. of Aubrey's is also in the Library, and contains curious researches frequently re- ferred to by antiquaries. The collection likewise contains MSS. of Pappus Alexandrinus, Statins, Jordanus, Nemorarius, Malpighius, John Robins, &c. The Catalogue of Miscellaneous Literature is peculiarly valuable, as containing autograph letters of the majority of distinguished individuals throughout Europe since the first forma- tion of the Society ; for instance, of Newton, Leibnitz, Wren, Heve- lius, Huygens, Lister, Ray, Wllloughby, &c. &c.
The Library possesses, besides, a large collection of Maps and Charts, and many Engravings ; but of these no catalogue is as yet published.
In almost every department of Science, the Library contains all the most valuable works, especially in the mathematical sciences.
In the Miscellaneous division of the Library, the largest propor- tion of which was acquired by the bequest of the Earl of Arundel, the Library possesses some very interesting books, especially some of the early works of the fifteenth and sixteenth centuries, and many Editiones principes of the Classics. The majority of these came into the possession of the Earl of Arundel by the purchase of the library of the celebrated Bilibaldus Pyrckheinier ; particularly the jurists and the early reformers. Of these, the first editions of many of Lu- ther's tracts are interesting. There are, besides, some curious col- lections of Italian and Spanish poetry.
The earliest printed book in the Library is a splendid copy upon vellum of the Decretals, printed by Fust in 1465, and Tully's Offices, also on vellum, by Fust in 1466 ; and there are specimens of many of the early German and Italian presses. Of our own, there are copies of Caxton's second edition of Chaucer's Canterbury Tales, and Pynson's first edition of the same works, the first half of which was revised by Caxton. Neither have dates ; but the former is sup- posed by Tyrwhit to have been printed about 1482, and the latter about 1493. With these exceptions, the Library contains but few early English books ; for the second folio edition of Shakspeare can- not be so called, as there are scientific books of an earlier date than this in the Library. There are also the majority of the books printed by the Record Commission and by the Oriental Translation fund.
