A letter from an American : now resident in London, to a Member of Parliament, on the subject of the restraining proclamation; and containing strictures on Lord Sheffield's pamphlet, on the commerce of the American states. Said to be written by William Bingham, Esquire; late agent for the Congress of the United States of America, at Martinico. To which are added, Mentor's reply to Phocion's letter; with some observations on trade, addressed to the citizens of New-York.