France overrun with fugitive galley-slaves--Life and property constantly in danger--Vidocq offers his services to the cause of law and order--M. Henri refuses to accept his cooperation--Vidocq taken again, and again offers M. Henri his services--A compact finally made with him--Becomes a “mouton” and renders very useful service--Brings about the capture of the notorious receiver--Routs out a robbers’ home kept by Mother Noel--Does good work in the discovery and arrest of Fossard and others who robbed the Royal Library of a great collection of old coins and medals--Vidocq, the father of the French Detective Police--His portrait--A man of unexampled courage, fertility of resource and great physical strength--The “police provocative,” an invention of the day--The so-called conspiracy of Colmar--Saumur and the betrayal of La Bédoyère. The state of France during the period which has just been described was deplorable. There was little security for property, and life was constantly in danger. Whole bands of fugitive galley-slaves were at large, pursuing their evil courses with the utmost daring and effrontery. They were apprehended from time to time, but were acquitted, when arraigned, for want of evidence; witnesses as to identity were not forthcoming, and unless caught red-handed there were no proofs of guilt. To surprise them and take them into custody knowledge of their domicile was essential; and they were so cunning and evasive that it was not easy to ascertain this fact. It was under these circumstances that justice in France, in its eagerness to check these depredations and to protect the deserving, industrious population, secretly sought the aid of spies and informers willing to work against the criminal fraternity. Vidocq was one of the first to go over. He was weary of the life he led, the unceasing anxiety, the constant fear of recognition by old associates, the incessant blackmail to which he was subjected; and to escape re-arrest he was driven in self-defence to retaliate and offer his services to the cause of order. Matters were brought to a crisis when he was called upon to participate in a series of robberies to be perpetrated by old convicts, whose hands were already bloodstained. Vidocq, realising that whether he refused this proposal or not he must be compromised sooner or later in other infamous deeds, resolved to go in person to the Chief of Police, at that time a M. Henri, an excellent officer, who rendered eminent service in his day. Vidocq confided in the Chief, and explained his situation, saying, if his presence in Paris was tolerated and he was assured immunity from arrest, he could promise much valuable information. He could lay his hands upon great numbers of convicts at large, knowing precisely their places of residence and many of their plans. M. Henri at once declined to enter into any compact of the kind. All he would say was: “I have no objection to