Three letters : addressed to the people of the United States, which have lately appeared under the signature of "A South-Carolina planter." The first, on the case of Jonathan Robbins. The second, on the recent captures of the British cruisers, and the right of a citizen to expatriate himself. The third, on the claims of the British creditors, and the proceedings of the British commissioners under the sixth article of Mr. Jay's treaty. By Charles Pinckney, senator in Congress, for South-Carolina.