_The Wholesale Destruction of Medical Literature during the Early Centuries of the Christian Era._--The invasion of Rome in 410 A. D. was one of the first events which entailed a serious loss of the Greek medical books that had been accumulating for several centuries in that city. Fortunately, not a few of these works were rescued in time by the church authorities and deposited for safe keeping in the various monasteries scattered all over the Roman Empire. A still more serious destruction of books occurred about the year 638 A. D., when Amrou, a famous Arabian warrior, captured Alexandria and--under the instructions of his master, Omar ben Khattab--destroyed the greater part of the contents of the famous libraries located in that city. The narrative of this event, as told by Lucien Le Clerc, is as follows:-- John the Grammarian,[43] who was living at that time in Alexandria, held the following conversation with Amrou on a certain occasion: “You have inspected all the edifices of Alexandria, and have sequestrated all their contents. I have no objections to your appropriating everything that may be of use to you; there are certain things, however, which you may not wish to possess, but which are highly prized by us.” “What are those objects?” inquired Amrou. “The works on philosophy, which are contained in the public libraries,” John replied. “I can do nothing about them without a special order from the Prince of Believers, Omar ben Khattab,” was the answer given by Amrou. John’s wish having in the meantime been conveyed by the General to Omar, the latter sent this reply:-- “As to the books of which you speak, I have this to say. If their contents agree with what is written in the word of God, the books are of no use to us, the Holy Writ being sufficient for our guidance. But if they are at variance with God’s word, then surely they should be destroyed.” Amrou therefore ordered all the books to be sent to the bathing establishments of Alexandria, to be used as fuel in heating the baths. So great was the number of books contained in the libraries that it took six months to consume them all. (Sismondi questions the correctness of this account.)