This physician had learnt the theory of his profession in Greek, Persian, Turkish, Arabic, Latin, Syriac, and Hebrew books; he was an experienced natural philosopher, and fully understood the good and bad qualities of plants and drugs. As soon as he was informed of the king's distemper, and understood that his physicians had given him over, he found means to present himself before him. "I know," said he, after the usual ceremonials, "that your majesty's physicians have not been able to heal you of the leprosy; but if you will accept my service, I will engage to cure you without potions, or external applications." The king listened to what he said, and answered, "If you be able to perform what you promise, I will enrich you and your posterity. Do you assure me that you will cure my leprosy without potion, or applying any external medicine?" "Yes, Sire," replied the physician, "I promise myself success, through God's assistance, and to-morrow, with your majesty's permission, I will make the trial." The physician returned to his quarters, made a hollow mace, and at the handle he put in his drugs; he made also a ball in such a manner as suited his purpose, with which next morning he presented himself before the king, and falling down at his feet, kissed the ground. The physician Douban rose up, and after a profound reverence, said to the king, he judged it meet that his majesty should take horse, and go to the place where he used to play at mall. The king did so, and when he arrived there, the physician came to him with the mace, and said, "Exercise yourself with this mace, and strike the ball until you find your hands and body perspire. When the medicine I have put up in the handle of the mace is heated with your hand, it will penetrate your whole body; and as soon as you perspire, you may leave off the exercise, for then the medicine will have had its effect. Immediately on your return to your palace, go into the bath, and cause yourself to be well washed and rubbed; then retire to bed, and when you rise to-morrow you will find yourself cured." The king took the mace, and struck the ball, which was returned by his officers who played with him; he played so long, that his hands and his whole body were in a sweat, and then the medicine shut up in the handle of the mace had its operation, as the physician had said. Upon this the king left off play, returned to his palace, entered the bath, and observed very exactly his physician had prescribed to him.