His Critique on the Tragedies of Sophocles 15 His mode of Life and Habits 16 His "Mariamne" successful 16 1722. Dispute between the Poets Jean Baptiste Rousseau and Voltaire 17 Insult offered Voltaire by the Chevalier de Rohan 17 He challenges de Rohan, and is sent to the Bastille 18 1728. Ætat. 34. He visits England and reads Locke and Newton 18 His return to Paris 19 The Clergy become suspicious of him, and aim at his Ruin 19 Increase of his Fortune 20 Reasons of his purchasing the Estate of Voltaire, and assuming that name 21 Becomes attached to the Marchioness du Châtelet 21 His "Brutus" and "Eriphyle" unsuccessful 22 1732. Ætat. 38. Great success of "Zaire" 22 "Histoire de Charles XII." 23 "Siècle de Louis XIV." projected by Voltaire 23 Mademoiselle Lecouvreur, an Actress, denied the Rites of Sepulture 23 Voltaire's "Lettres sur les Anglais" publicly burnt 23 He retires to the Château de Cirey with the Marquis and Marchioness du Châtelet 24 Their philosophical Studies 25 He writes "Alzire," "Mérope," "Mahomet," &c. 25 "Essay on the Manners and Spirit of Nations" 25 Madame de Graffigny's Visit to Madame du Châtelet at Cirey; her Letters 26 1738. Ætat. 44. Voltaire writes "La Pucelle," the Maid of Orléans 28 Is attacked by the Abbé des Fontaines and Jean Baptiste Rousseau 31 Alarm as to the Printing of "La Pucelle" 33 His Correspondence with Frederic II. 35 1740. Letters of Frederic 37 Interview of the King of Prussia and M. de Voltaire at the Castle of Meuse, near Clèves 39 Maupertuis President of the Berlin Academy 39 Frederic's former Work against the Principles of Machiavel, the "Anti-Machiavel" 40 Character of Frederic 41 1742. War against Maria Theresa, on the Death of Charles VI. her Father 42