In his fourth number, (Oct. 10th,) M. Topin takes up the claim made for Fouquet, whose case differs from all the others in the fact that he was a prisoner of state by sentence of a judicial tribunal. Fouquet's claims were warmly pressed by a very able literary advocate, Paul Lacroix, (Bibliophile Jacob,) in a work published in 1830. But here again the difficulty of dates is insurmountable. Fouquet died in 1680, and there is no proof of the appearance of the Man with the Iron Mask until after that period. We pass on to another. In the year 1677, the Duke of Mantua was Charles IV. of the illustrious house of Gonzaga. He was young, careless, dissipated, and extravagant. Spending most of his time in Venice, he seldom visited his duchy, except for the purpose of raising money. He gradually fell into the hands of usurious lenders, and continued to obtain the sums he wanted by anticipating, through them, the receipt of the taxes and imposts of his duchy by several years. The Marquisate of Montferrat was among his dependencies. Its little capital, Casal, a fortified place on the Po, fifteen leagues east of Turin, was a point of great strategic importance, and essential to the safety of Piedmont. The court of Turin would not, of course, consent to its possession by France. But to France it was of the highest value, as with Pignerol and Casal it would be master of the situation. This place Louis XIV. wanted to buy, and Charles IV. was perfectly willing to sell it. Ercolo (Hercules) Antonio Mattioli, a young nobleman of the court of Mantua, at this time thirty-seven years of age, was high in favor with the reigning duke. Through Giuliani, an Italian journalist, D'Estrades, Louis XIV.'s ambassador at Venice, sounded Mattioli, and finally, through him, succeeded in opening a negotiation with the duke for the sale of Casal to France. All three met at Venice in March, 1678, discussed terms, and agreed upon one hundred thousand crowns as the price of the cession. Mattioli then went to Paris to sign the treaty in the name of his master the duke. The treaty was completed in December, 1678, and after its signature, Mattioli was received by Louis XIV. in secret audience, presented by the king with a rich diamond ring and four hundred double _Louis d'or_, with the promise of a far greater amount of money, the appointment of his son among the royal pages, and a valuable endowment for his mother. The intrigue and negotiation had been admirably managed and crowned with perfect success. Of all who had any interest opposed to the French possession of Casal, not one had the slightest suspicion, and it would have been difficult to imagine the existence of the smallest element of failure in the enterprise.