Besides the representations of angels in art in accordance with the imagination of individual artists, there are two important classes of angelic subjects, one of which rests upon the authority of the Scriptures, and the other upon that of the sacred legends. A comprehensive treatment of these works would require several volumes of the size of this book; but I will here give a suggestive outline of them. The first mention of angels in the Old Testament occurs in the third chapter of Genesis, when it is related that cherubims were placed at the east of the Garden of Eden, to keep the way to the Tree of Life. Good pictures of this subject are as rare as they are beautiful. In them the exquisite garden, the radiant cherubim, and the dazzling light from the flaming sword, combine in producing a glorious effect. In connection with the story of Abraham, angels frequently appear. The sacrifice of Isaac is always an interesting subject, symbolizing, as it does, in the submission of Isaac, that of Jesus, and in the willingness of Abraham to give his son in sacrifice, that of the Divine Father to give his well-beloved Son for the salvation of men. The appearance of the angel to prevent the consummation of the sacrifice has been painted many times, notably by Andrea del Sarto, whose poetical pictures of this scene are in the Dresden and Madrid galleries. The picture by Rembrandt is powerful, and painfully realistic. It is in the Hermitage at St. Petersburg. The same scene in the Church of Santa Maria della Salute, Venice, is by Titian, and is among the famous works of this great master. Our illustration after a picture by Il Sodoma, in the Cathedral of Pisa, is in the best style of that master, who has been called the pride of the Sienese school. His acknowledged power to render intense feeling is seen in the face of Abraham, while the angel is an example of his conception of beauty; the submissive Isaac, missing the pressure of his father’s hand from his shoulder, without changing his position, turns his eyes to discover the reason for the delay of the expected blow. In the story of Hagar an angel twice appears, and one is surprised that these charming subjects have so rarely been [Illustration: IL SODOMA.--THE SACRIFICE OF ABRAHAM.] painted, while the more disagreeable expulsion of Hagar from the home of her youth has been frequently represented; the picture of this scene by Guercino, in the Brera at Milan, is famous, and certainly tells the story of “Cast out the bondwoman and her son” with directness; but there is an element of vulgarity in it that so detracts from its good qualities as to make one wonder that it could have been so much admired.