In Wagner's beautiful opera of Parsifal, based upon the legend of the Holy Grail, reference to the same custom is more than once evident. The second act opens with a scene representing the enchanted castle of Klingsor; the magician himself is seen gazing into a bright metallic mirror, in which he sees Parsifal approaching and recognizes and fears him as the promised guiltless one--the true king and guardian of the Grail--an office to which he himself had once aspired. In fact the Grail itself, in its earliest mythical and traditional form, as well as in its later development as a distinctly Christian symbol, was an instrument of divination and prophecy. The Druids had their basin, sometimes filled with aromatic herbs, sometimes with the blood of the sacrificed victim; but in either case it was potent for securing the proper psychic condition in the officiating priest or soothsayer; and while Arabic and Indian myths present the same idea, sometimes as a cup of divination, and sometimes as a brilliant stone, the British Islands were the main source of the traditions which eventually culminated in the legends of the Holy Grail, with its full store of beautiful and touching incidents, prophecies, and forms of worship. In each the special guardians and knights of the Grail appear, with Parsifal, the simple-minded, pure and pitiful knight as its restorer and king when lost or in unworthy hands. In the German version of the twelfth century as given by Wolfram, in his Parzival, the Grail is a beautiful, sacred stone, enshrined in the magnificent temple at Montsalvat, guarded by the consecrated knights and the sick and erring, but repentant, King Amfortas. While the unhappy king was worshipping with gaze intent upon the Sacred Emblem, suddenly letters of fire surrounded it and he read the cheering prophecy: "In the loving soul of a guiltless one Put thy faith--Him have I chosen." Kufferath remarks, "The religious emblem soon became a symbolic object--it revealed to its worshippers the knowledge of the future, the mystery of the world, the treasures of human knowledge, and imparted a poetic inspiration." So it comes to pass that in the legend in its latest form--the splendid work of the Master of Bayreuth, the Holy Grail, as a chalice and Christian emblem, is still endowed with the same miraculous power, and is rescued from the unfortunate guardianship of Amfortas by the "loving soul of a guiltless one"--the simple, tried, and much-enduring Parsifal, miraculously promised long before by the Grail itself. It will be seen, then, that crystal-gazing in its various forms has, from the earliest times, been practised with great ceremony for the purpose of acquiring knowledge concerning affairs and events unknown and often not discoverable by ordinary methods.