The Hegira, or flight of Mohammed from Mecca to Medina, corresponds with the year 622 of our era, and the supposed burning of the Alexandrian library by Amrou, the general of the Caliph Omar, with the year 641. This is the period of the deepest barbarism among the Saracens, and this event, doubtful as it is, has left a melancholy proof of their contempt for letters. A century had scarcely elapsed from the period to which this barbarian outrage is referred, when the family of the Abassides, who mounted the throne of the Caliphs in 750, introduced a passionate love of art, of science, and of poetry. In the literature of Greece, nearly eight centuries of progressive cultivation succeeding the Trojan war had prepared the way for the age of Pericles. In that of Rome, the age of Augustus was also in the eighth century after the foundation of the city. In French literature, the age of Louis XIV. was twelve centuries subsequent to Clovis, and eight after the development of the first rudiments of the language. But, in the rapid progress of the Arabian empire, the age of Al Mamoun, the Augustus of Bagdad, was not removed more than one hundred and fifty years from the foundation of the monarchy. All the literature of the Arabians bears the marks of this rapid development. Ali, the fourth Caliph from Mohammed, was the first who extended any protection to letters. His rival and successor, Moawyiah, the first of the Ommyiades (661-680), assembled at his court all who were most distinguished by scientific acquirements; he surrounded himself with poets; and as he had subjected to his dominion many of the Grecian islands and provinces, the sciences of Greece under him first began to obtain any influence over the Arabians. After the extinction of the dynasty of the Ommyiades, that of the Abassides bestowed a still more powerful patronage on letters. The celebrated Haroun al Raschid (786-809) acquired a glorious reputation by the protection he afforded to letters. He never undertook a journey without carrying with him at least a hundred men of science in his train, and he never built a mosque without attaching to it a school.