Voltaire, in his "Age of Louis XIV.," was the first to call special attention to this mystery, and since then numerous conjectures have been made as to who the Iron Mask really was. One writer has suggested that he was an illegitimate son of Anne of Austria, the queen-mother. Another identifies him with a supposed twin brother of Louis XIV., whose birth Richelieu had concealed. Others make him the Count of Vermandois, an illegitimate son of Louis XIV.; the Duke of Beaufort, a hero of the Fronde; the Duke of Monmouth, the English pretender of 1685; Fouquet, Louis's disgraced minister of finance; a son of Cromwell, the English protector; and various other wild and unfounded guesses. After all has been said, the identity of the prisoner remains unknown. Mattioli, a diplomatic agent of the Duke of Mantua, who was long imprisoned at Pignerol and at Sainte Marguerite, was for a long time generally thought to be the Iron Mask, but there is good reason to believe that he died in 1694. Conjecture has exhausted itself, and yet the identity of this strange captive remains a mystery, and is likely always to continue so. The fact that all the exalted personages of the day can be traced renders it probable that the veiled prisoner was really an obscure individual, whom the caprice of Louis XIV. surrounded with conditions intended to excite the curiosity of the public. There are on record other instances of imprisonment under similar conditions of inviolate secrecy, and it is not impossible that the king may have endeavored, for no purpose higher than whim, to surround the story of this one with unbroken mystery. If such were his purpose it has succeeded, for there is no more mysterious person in history than the Man with the Iron Mask. _VOLTAIRE'S LAST VISIT TO PARIS._ Never had excitable Paris been more excited. Only one man was talked of, only one subject thought of; there was no longer interest in rumors of war, in political quarrels, in the doings at the king's court; all admiration and all sympathy were turned towards one feeble old man, who had returned to Paris to die. For twenty-seven years he had been absent, that brilliant writer and unsurpassed genius, the versatile Voltaire. His facile pen had given its greatest glory to the reign of Louis XV., yet for more than a quarter of a century he had been exiled from the land he loved, because he dared to exercise the privilege of free speech in that land of oppression, and to deal with kings and nobles as man with man, not as reverent worshipper with divinity. Now, in his eighty-fourth year of age, he had ventured to come back to the city he loved above all others, with scarcely enough life left for the journey, and far from sure that power would not still seek to suppress genius as it had done in the past.