The Caliph Chasid of Bagdad was sitting one fine summer afternoon comfortably on his divan; he had slept a little, for it was a sultry day, and he looked quite refreshed after his nap. He smoked a long rosewood pipe, sipped now and then a little coffee which a slave poured out for him, and stroked his beard contentedly whenever he had enjoyed it. In short, it could be seen at a glance that the Caliph felt very comfortable. At such a time it was easy to approach him, as he was very good-tempered and affable, wherefore his Grand Vizier Mansor visited him every day about this time. This afternoon he came as usual, looking, however, very grave, a rare thing for him. The Caliph took the pipe out of his mouth and said: 'Why dost thou make so grave a face, Grand Vizier?' The Grand Vizier folded his arms across his breast, bowed to his master and answered: 'Master! whether I assume a grave appearance I know not, but down below in the palace stands a pedlar who has such fine wares that it vexes me that I have no money to spare.' The Caliph, who had long desired to rejoice the heart of his Grand Vizier, ordered his black slave to fetch the pedlar. In a few moments the slave returned with him. He was a stout little man, swarthy in the face, and dressed in rags. He carried a box in which he had all sorts of wares, pearls, and rings, pistols with richly inlaid stocks, goblets, and combs. The Caliph and his Vizier inspected everything, and the Caliph at last bought for himself and Vizier a pair of pistols, and for the Vizier's wife a comb. As the pedlar was about to close his box again, the Caliph caught sight of a little drawer, and asked whether it also contained some wares. The pedlar pulled out the drawer, and exhibited a snuff-box containing a black powder and a piece of paper with peculiar writing on it, which neither the Caliph nor Mansor could read. 'These things were given to me one day by a merchant who found them in the streets of Mecca,' said the pedlar. 'I know not what they are; but you may have them for a small sum, for they are of no use to me.' The Caliph, who was very fond of having old manuscripts in his library, though unable to read them, bought both paper and box and dismissed the pedlar. Still he thought he would like to know what the writing meant, and asked the Vizier if he did not know anybody who might decipher it. 'Most gracious lord and master,' answered the latter, 'near the Great Mosque lives a man called Selim the learned; he knows all languages. Send for him; perhaps he can explain these mysterious signs.'