Alexandrian Library, a collection of books formed by Ptolemy I. and Ptolemy II. of Egypt, and probably the largest prior to the invention of printing. It was founded, it is said, at the suggestion of Demetrius Phale-reus, who, when a fugitive at the Egyptian court, spoke with admiration of the public libraries at Athens. Demetrius was appointed superintendent, and diligently employed himself in the collection of the literature of all nations, Jewish, Chaldee, Persian, Ethiopian, Egyptian, Greek, Roman, etc. According to Eusebius, there were 100,000 volumes in the library at the death of Ptolemy Philadelphus; and subsequently the number was increased to 700,000. The rolumina or rolls, however, contained far less than a printed volume; as, for instance, the "Metamorphoses" of Ovid, in 15 books, would be considered as 15 volumes. During the siege which Caesar stood in Alexandria, a large part of the library was burned. Gibbon asserts that the old library was totally consumed, and that the collection from Perga-mus, which was presented by Mark Antony to Cleopatra, was the foundation of the new one, which continued to increase in size and reputation for four centuries, until dispersed by Theophilus, patriarch of Alexandria, at the destruction of the Serapeum, about A. D. 390. Still the library was reestablished; and Alex-andria continued to flourish as one of the chief seats of literature until it was conquered by the Arabs in 640. The library was then burned, according to a story of very questionable authenticity, in consequence of the fanatic decision of the caliph Omar: "If these writings of the Greeks agree with the Book of God, they are useless and need not be preserved; if they disagree, they are pernicious and ought to be destroyed." Accordingly, it is said, they were employed to heat the 4,000 baths of the city; and such was their number, that six months were barely sufficient for the consumption of the precious fuel.

There is no doubt, however, that after 040 the library ceased to exist as a public institution. Connected with the library was a college, or retreat for learned men, called the museum, where they were maintained at public expense.