Of the monuments of medieval missionary work very few can surpass in interest the letters written from China by John of Monte Corvino, Archbishop of Khan-balig, and Andrew of Perugia, Bishop of Zaitun; arid many persons will be grateful to the Council of the Royal Asiatic Society for printing a more accurate text of these letters than has hitherto been available. The letters, together with most of what is known of the history of the missions to the Far East, of which the writers were members, are found in a single MS. which is preserved in the Bibliothèque Nationale at Paris. The Librarians, whose extreme courtesy and kindness have made the following transcript possible, inform me that this MS. is now numbered “Latin 5006”, and that it dates from the first half of the fourteenth century. It contains 192 leaves, parchment, measuring Om. 20 × 0 m. 15. The credit of discovering the letters appears to belong to Luke Wadding, the voluminous historian of the Minor Friars, who was born at Waterford 16 October, 1588, and died 18 November, 1657, or to an unnamed friend of his.