Now as regards the works of Mercury ‘Alí; there lived once at Cairo,[FN#215] in the days of Saláh the Egyptian, who was Chief of the Cairo Police and had forty men under him, a sharper named Ali, for whom the Master of Police used to set snares and think that he had fallen therein; but, when they sought for him, they found that he had fled like zaybak, or quicksilver, wherefore they dubbed him Ali Zaybak or Mercury Ali of Cairo. Now one day, as he sat with his men in his hall, his heart becam...