One of the most important elements in the proper painting of seraphs and cherubs was the use of color, while greater freedom was permitted in the portrayal of other angelic orders. In a Glory, for example, the inner circle should be glowing red, the symbol of love; the second, blue, the emblem of light, which again symbolizes knowledge. Angelic symbolism in its purity makes the “blue-eyed seraphim” and the “smiling cherubim” equally incorrect, since the seraph should be glowing with divine love, and the face of the cherub should be expressive of serious meditation,--as Milton says, “the Cherub Contemplation.” The familiar cherubim beneath Raphael’s famous Madonna di San Sisto, in the Dresden Gallery, are exquisite illustrations of this thoughtfulness. The colors of the oldest pictures, of the illuminated manuscripts, the stained glass, and the painted sculptures were most carefully considered. Gradually, however, the color law was less faithfully observed, until, at the end of the fifteenth and the beginning of the sixteenth centuries, it was not unusual to see the wings of cherubim in various colors, while cherub heads were represented as floating in clouds with no apparent wings. Two pictures of world-wide fame illustrate this change,--Raphael’s Madonna, mentioned above, and Perugino’s Coronation of the Virgin. In the first, the entire background is composed of seraphs and cherubs apparently evolved from thin blue air, and in constant danger of disappearing in the golden-tinted background. In the second, the multi-colored wings of the floating cherubim are beautiful and the harmony of tones is exquisite, but they represent an innovation to which one must become more and more accustomed as artists are less reverent in their work. The five angelic choirs which follow the seraphim and cherubim are not familiar to us in works of art, although they were painted with great accuracy in the words of the mediæval theologians. When archangels are represented merely as belonging to their order, and not in their distinctive offices, they are in complete armor, and bear swords with the points upwards, and sometimes a trumpet also. [Illustration: FRA ANGELICO.--A GLORY OF ANGELS.] Angels are robed, and are represented in accordance with the work in which they are engaged. Strictly speaking, the wand is the angelic symbol, but must be frequently omitted, as when the hands are folded in prayer, or musical instruments are in use, and in a variety of other occupations.