The Turks, having stripped their prisoners and clothed them in a kind of rough uniform, fastened chains round their necks and marched them through the town to the marketplace, where they were exhibited for sale much as cattle are at the present day. They were carefully inspected by the dealers, who looked at their teeth, felt their muscles, made them run and walk--with loads and without--to satisfy themselves that they were in good condition, and finally selected their victims. Vincent was bought by a fisherman who, finding that his new slave got hopelessly ill whenever they put out to sea, repented of his bargain and sold him to an alchemist. In the West, as well as in the East, there were still men who believed in the Philosopher's Stone and the Elixir of Life. By means of the still undiscovered Stone they hoped to change base metals into gold, while the equally undiscovered Elixir was to prolong life indefinitely, and to make old people young. Vincent's master was an enthusiast in his profession and kept ten or fifteen furnaces always burning in which to conduct his experiments. His slave, whose business it was to keep them alight, was kindly treated; the old man soon grew very fond of him and would harangue him by the hour on the subject of metals and essences. His great desire was that Vincent should become a Mohammedan like himself, a desire which, needless to say, remained unfulfilled, in spite of the large sums of money he promised if his slave would only oblige him in this matter. The old alchemist, however, had a certain reputation in his own country. Having been sent for one day to the Sultan's Court, he died on the way, leaving his slave to his nephew, who lost no time in getting rid of him. Vincent's next master was a Frenchman who had apostatized and was living as a Mohammedan on his farm in the mountains. This man had three wives, who were very kind to the poor captive--especially one of them, who, although herself a Mohammedan, was to be the cause of her husband's conversion and Vincent's release. She would go out to the fields where the Christian slave was working and bid him tell her about his country and his religion. His answers seemed to impress her greatly, and one day she asked him to sing her one of the hymns they sang in France in praise of their God. The request brought tears to Vincent's eyes. He thought of the Israelites captive in Babylon, and of their answer to a similar demand. With an aching heart he intoned the psalm, "By the waters of Babylon," while the woman, strangely impressed by the plaintive chant, listened attentively and, when he had ended, begged for more.