It now first dawned upon the Caliph that the strange and invisible substance which he had picked up in the dungeon, and which he still carried in his hand, possessed indeed the marvellous property of rendering him entirely invisible to other men. This accounted for the remarkable panic of his jailer, who, when he looked into, and even entered his dungeon, failed to see him; it explained why the soldiers had permitted him to leave the building unmolested, why the horseman had nearly ridden over him, and why the clown who had just passed had, without knowing it, nearly brained him with his load. Much comforted and strengthened by the discovery of this wonderful exemption from observation which he now enjoyed, he walked on briskly, till the sun, being now high in the heavens, and the heat very great, he came to a village, and entering boldly an inn there, and passing through into an empty apartment, he lay down upon a not very soft divan he found in it, and straightway fell asleep. The Caliph being tired with the walk and the excitement of the morning, slept so long and soundly that it was night and quite dark when he awoke. And being even then but half awake he did not realize that he was no longer in the castle-dungeon; therefore, perceiving that it was not yet light, he turned over and went to sleep again. In a few hours' time, in the midst of a dream that he was in his own palace at Bagdad and presiding at some great feast, he awoke once more, saw that it was beginning to be light, remembered where he was, and found himself exceedingly hungry. Going, therefore, very quietly into the next apartment, he found the innkeeper lying there soundly asleep, and on the table the remains of a substantial supper. At once seating himself, the Caliph was not long in finishing the repast and assuaging the pangs of hunger. Having all his life been used to eat and drink whatever he required, without any thought of payment, it is very likely that he might have eaten his meal and departed without the least concern or thought of the fact that he possessed at that moment nothing to pay for it. However, it so fell out that he was enabled to recompense his involuntary host very handsomely. For after he had finished eating, and before he rose from his seat, he heard a slight rustling sound outside the room, as though some one were stealthily approaching. Now the Caliph, before lying down to rest on the previous afternoon, had taken the precaution to bestow the mysterious and wonderful charm he had picked up, in a place of safety. He had put it inside his turban, in such a way that he could feel it pressing like a soft elastic pad upon his forehead. And therefore, in virtue of his contact with that charm, he was still invisible to every other human being.