Nothing came of this arrest, which Vidocq took quite as a joke, although he was detained in the Conciergerie for three months and his business suffered. Yet, afterwards, the police would not leave him alone. Old animosities had never disappeared, and they were revived when Vidocq occasionally turned his hand to his old work and caught someone whom the regular police could not find. He had started a sort of "trade protection society," by which, on payment of a small annual fee, any shopkeeper or business man could obtain particulars concerning the solvency of new clients. The number of subscribers soon exceeded 8,000, and Vidocq, in one of his published reports, fixed the amount he had saved his customers at several thousands of pounds. A fresh storm burst over him when he unmasked and procured the arrest of a long-firm swindler, before the police knew anything of the case. Once more he was arrested, in 1842; his papers were impounded, there were rumours of tremendous disclosures, family scandals, crimes suppressed--all manner of villainies. No doubt he had made himself the "intermediary" in matters not quite savoury, but the worst things against him were an unauthorised arrest and a traffic in decorations very much on the Grévy-Wilson lines of later days. The prejudice against him must have been strong, and the case [Illustration: THE CONCIERGERIE, PALACE OF JUSTICE, PARIS.] ended in a sentence of eight years' imprisonment, which was, however, reversed on appeal. He was much impoverished by his lawsuits, and one of his last proceedings was to appear before a London audience dressed, first as a French convict in chains, then in the various disguises he had used in following up malefactors. Although his lecture was in French, he seems to have attracted large audiences at the Cosmorama. Sir Francis Burdett was a great patron and supporter of Vidocq, and was in the habit, whenever he visited Paris, of inviting the old thief-taker to dine with him at the Trois Frères Restaurant in the Palais Royal. Vidocq died in penury in 1857 at a very advanced age.