Raphael (Hebrew ',tin, " God heals"), an angel who in human disguise and under the name of Azarias ("Yahweh helps") accompanies Tobias in his adventurous journey and conquers the demon Asmodaeus (Book of Tobit). He is said (Tob. xii. 15) to be "one of the seven holy angels [archangels] which present the prayers of the saints and go in before the glory of the Holy One." In the Book of Enoch (c. xx.) Raphael is "the angel of the spirits of men," and it is his business to "heal the earth which the angels have defiled." In later Midrash Raphael appears as the angel commissioned to put down the evil spirits that vexed the sons of Noah with plagues and sicknesses after the Flood, and he it was who taught men the use of simples and furnished materials for the "Book of Noah," the earliest treatise on materia medica.