a medical school. There is evidence to show that physicians, pharmacists and oculists were examined and given certifi- cates before being allowed to practise their professions. In the manuals for the guidance of officials responsible for law enforcement, their duties with respect to phlebotomists, cuppers, physicians, surgeons, bone-setters and druggists are clearly set forth, indicating a certain measure of state control. Ibn-al-Nafis, a Syrian physician 'who would not prescribe medicine when diet sufficed', in a commentary on ibn-Sina contributed a clear conception of the pulmonary circulation of the blood three centuries before the Spaniard Servetus, to whom the discovery is usually credited. The only major Arabic medical works of the thirteenth century were treatises by two Syrian oculists. One of them, Khalifah ibn-abi-al- Mahasin of Aleppo, was so confident of his surgical skill that he did not hesitate to remove a cataract from a one-eyed man. To this century too belongs the most distinguished Arabic historian of medicine, Ahmad ibn-abi-Usaybiah of Damascus. He compiled biographies of some 400 Arab and Greek physicians and scientists. All these men, however, lived in the late twilight of Islamic science.
Saladin and his heirs continued Nur-al-Din's interest in building schools and mosques. It was Saladin who intro- duced from Syria into Egypt the dervish 'monastery' and the collegiate mosque to inculcate orthodox Sunnism and combat the widely held Shiite doctrine. In Jerusalem he built a hospital, a school and a monastery all bearing his name. The Ayyubid school of Syrian architecture was continued in Mamluk Egypt, where it is still represented by some of the most exquisite monuments Arab art ever pro- duced. Strength, solidity and excessive decoration char- acterize this school. Its decorative motifs assume infinite grace on its durable material of fine stone. In the thirteenth century Egypt received fresh Syro-Mesopotamian influences through refugee artists and artisans who had fled Damascus, Baghdad and Mosul during the Mongol invasions. The
