On the 11th of September this brigantine was seized as a slaver. During the correspondence with the British officers in relation to the Louisa Beaton, an order was given to the officer of the cutter, to prevent the Chatsworth from landing the remaining part of her cargo. The master immediately called on board the Perry, with the complaint, that his vessel had been seized on a former occasion, and afterwards released by the commodore, with the endorsement of her nationality on the log-book. Since then she had been repeatedly searched, and now was prevented from disposing of her cargo; he wished, therefore, that a definite decision might be made. A decision was made by the instant seizure of the vessel. Information from the master of the Louisa Beaton, that the owner of the Chatsworth had in Rio acknowledged to him that the vessel had shipped a cargo of slaves on her last voyage, and was then proceeding to the coast for a similar purpose--superadded to her suspicious movements, and the importance of breaking up this line of ostensible traders, but real slavers, running between the coasts of Brazil and Africa--were the reasons leading to this decision. On announcing the decision to the master of the Chatsworth, a prize crew was immediately sent on board and took charge of the vessel. The master and supercargo then drew up a protest, challenging the act as illegal, and claiming the sum of fifteen thousand dollars for damages. The supercargo, on presenting this protest, remarked that the United States Court would certainly release the vessel; and the _proçuro_ of the owner, with other parties interested, would then look to the captor for the amount of damages awarded. The commander replied, that he fully appreciated the pecuniary responsibility attached to this proceeding. The master of the Louisa Beaton, soon after the supercargo of the Chatsworth had presented the protest, went on shore for the purpose of having an interview with him, and not coming off at the time specified, apprehensions were entertained that the slave-factors had revenged themselves for his additional information--leading to the seizure of the Chatsworth. At nine o’clock in the evening, three boats were manned and armed, containing thirty officers and men,--leaving the Perry in charge of one of the lieutenants. When two of the boats had left the vessel, and the third was in readiness to follow, the master of the Louisa Beaton made his appearance, stating that his reception on shore had been any thing but pacific. Had the apprehensions entertained proved correct, it was the intention to have landed and taken possession of the town; and then to have marched out to the barracoons, liberated the slaves, and made, at least for the time being, “free soil” of that section of country. In a letter to the commodore, dated September 14th, information was given to the following purport: