In the account of the Monophysites and Nestorians, I am deeply indebted to the Bibliotheca Orientalis Clementino-Vaticana of Joseph Simon Assemannus. That learned Maronite was despatched, in the year 1715, by Pope Clement XI. to visit the monasteries of Egypt and Syria, in search of Mss. His four folio volumes, published at Rome 1719 - 1728, contain a part only, though perhaps the most valuable, of his extensive project. As a native and as a scholar, he possessed the Syriac literature; and though a dependent of Rome, he wishes to be moderate and candid.