Absolutism, _l'arbitraire_, all through this period was making hay while the sun shone, and playing rare tricks with the liberties of the subject. Vincennes was a witness of strange things done in the name of the King's justice. Take the curious case of the Abbé Prieur. The Abbé had invented a kind of shorthand, which he thought should be of some use to the ministry. But the ministry would none of it, and the Abbé made known his little invention to the King of Prussia, a patron of such profitable things. But one of his letters was opened at the post-office by the _Cabinet Noir_, and the next morning Monsieur l'Abbé Prieur awoke in the dungeon of Vincennes. He inquired the reason, and in the course of months his letter to the King of Prussia was shewn to him. "But I can explain that in a moment," said the Abbé. "Look, here is the translation." The hieroglyphs, in short, were as innocent as a verse of the Psalms, but the Abbé Prieur never quitted his dungeon. A venerable and worthy nobleman, M. Pompignan de Mirabelle, was imprudent enough to repeat at a supper party some satirical verses he had heard touching Madame de Pompadour and De Sartines, the chief of police. Warned that De Sartines had filled in his name on a _lettre de cachet_, M. de Mirabelle called at the police office, and asked to what prison he should betake himself. "To Vincennes," said De Sartines. "To Vincennes," repeated M. de Mirabelle to his coachman, and he arrived at the dungeon before the order for his detention. Once a year, De Sartines made a formal visit to Vincennes, and once a year punctually he demanded of M. de Mirabelle the name of the author of the verses. "If I knew it I should not tell you," was the invariable reply; "but as a matter of fact I never heard it in my life." M. de Mirabelle died in Vincennes, a very old man. A Swiss, by name Thoring, in the service of Madame de Foncemargue, told a dream in which his mistress had appeared to him with this message: "You must assassinate the King, and I will save you. You will be deaf and dumb until the deed is accomplished." The man was clearly of unsound mind, but weak intellects were not allowed to murder kings in their sleep, and he was cast into Vincennes. Twenty years later he was seen chained by the middle to the wall of his cell, half naked and wholly mad.