A short time previous to the death of Mahmoud, some alterations not very material indeed, yet favorable on the whole to the United States, were made in the treaty concluded between their Government and that of Tunis in 1797. One of the amended articles provides--that no American merchant vessel shall be detained against the will of her captain in a Tunisian port, unless such port be closed for vessels of all nations, and that no American vessel of war should be so detained under any circumstances. This was considered by the British Government at variance with the terms of the engagement made with Admiral Freemantle in 1812, by which the armed vessels of nations at war with Great Britain were not to be suffered to leave a Tunisian port within twenty-four hours after the sailing of a British vessel; and the Consul was directed to ask for explanations on the subject from the Bey. Hassan who had by this time succeeded to the throne replied positively, that there was nothing contradictory in the two stipulations, and that this agreement had been made with the United States, merely in order to place them on a level with other nations. As the British Government had thought proper to make the inquiry, it is strange that it should have been satisfied with such an answer; however, under the condition of things then existing and the probabilities with respect to the future, it was certainly not worth while to press the matter further. The Pasha of Tripoli, notwithstanding the treaties made with Lord Exmouth in behalf of Sardinia and the Two Sicilies in 1816, and his protestations to the English and French Admirals three years after, sent out armed vessels to cruise against the commerce of the Italian States. When complaint was made of these depredations, Yusuf replied that the treaties were no longer binding, and that if those nations wished to remain at peace with him, they must pay him an annual tribute. To this insolent and unreasonable pretension, the King of Sardinia replied by fitting out a squadron composed of two frigates, a corvette and a brig, which sailed from Genoa in September 1825, and arrived before Tripoli on the 25th of that month. Before relating the proceedings of this expedition it will be proper to give some account of the place against which it was sent. The town of Tripoli stands on a rocky point of land projecting northwardly into the Mediterranean; it is surrounded by a high and thick wall, forming an unequal pentagon or figure of five sides of different lengths, of which the two northern are washed by the sea, the other three looking upon a sandy plain but partially cultivated. The circumference of the place is about three miles, and the area enclosed within the wall does not exceed one thousand yards square.