Whatever may be thought of the credibility of the legend, there can be no question that this ring is one of the most highly prized relics. It is of chalcedony, and its form seems to indicate that it was at one time set with a precious stone. On only four days in the year, March 19, the second Sunday in July, July 30, and August 2, can this unique ring be seen by the public. The betrothal ring of the Virgin is in the Capella del Santo Anello, in the left aisle of the Cathedral, where the celebrated painting by Perugino, the Spozalizio, now at Caen in Normandy, was preserved until 1797, when it was taken off by the French invaders. The ornate tabernaculum was executed by the goldsmith Cesarino del Roscetto in 1519. The espousal ring of St. Anne, mother of the Virgin Mary, was preserved in the monastery of St. Sylvester, at Rome. It is of unwrought silver, with a clear crystal set in the middle, surrounded by black spots and opaque at the back, so that it reflects images, just as does a mirror. On the festival of the betrothal of St. Anne, the eyes of those whose sight was weak were touched with the ring.[416] The curative results of this application were doubtless all that could be desired, more especially as weak sight is often caused by nervous depression, or nervous derangements. The body of St. Caius, martyred in 296 A.D., was exhumed from the Cemetery of Calixtus, in Rome, on the anniversary of the sainted pope’s birth, April 21, 1622, in the reign of Pope Gregory XV. Within the sepulchre were found three coins of Diocletian, in whose reign St. Caius (283–296 A.D.) received the papal crown, and also the pope’s ring, probably his signet, although no exact description of it has reached us.[417] In the succeeding century there is notice of another ecclesiastical signet-ring, for in a letter of St. Augustine (354–430) to Victorinus, the Church Father concludes with the words: “I have sent this epistle sealed with a ring which shows the profile-head of a man.”[418] As in the case of all the very early bishops’ rings, this one of St. Augustine was merely his personal signet and had no direct connection with his sacred office. A massive ring of Pope Pius II (Aeneas Sylvius Piccolomini, 1457–1464) has on the sides of the hoop the coats-of-arms of the Piccolomini and Tiara families; below the bezel are figures symbolical of the Four Evangelists. This interesting papal ring is in the collection of Dr. Albert Figdor, Vienna.[419]