CASIRI, MIGUEL (1710-1791), a learned Maronite, was born at Tripoli (Syria). He studied at Rome, where he lectured on Arabic, Syriac and Chaldee. In 1748 he went to Spain, and in 1763 he became principal librarian at the Escorial, a post which he appears to have held until his death. Casiri published a work entitled Bibliotheca Arabico-Hispana Escurialensis (176o-7o) . It is a catalogue of above 1,800 Arabic mss., which he found in the library of the Escorial; it also contains a number of quotations from Arabic works on history. The second volume gives an account of many geographical and historical mss., which contain valuable information regarding the wars between the Moors and the Christians in Spain. Casiri's work is not yet obsolete, but a more scientific system is adopted in Hartwig Derenbourg's incom plete treatise, Les Manuscrits arabes de l'Escorial (1884).