From Spain, by order of Congress, Jay proceeded to Paris to arrange, in conjunction with Franklin, Adams, Jefferson, and Laurens, the Definitive Treaty of Peace with England,--the most important diplomatic act of the eighteenth century; and we have the testimony of Mr. Fitzherbert, then the English minister resident in Paris, that "it was not only chiefly but SOLELY through his means that the negotiations of that period between England and the United States were brought to a successful conclusion." Mr. Oswald had arrived in Paris with a commission, in which the United States were mentioned under the designation of "colonies," but Jay, although his associates did not participate in his scruples, refused to begin negotiations without a preliminary recognition on the part of England of the Independence of the United States; and owing to his firmness a new commission was obtained from the king, in which that most essential point (as the sequel proved) was gained. Declining the appointment now tendered him by Congress of commissioner to negotiate a commercial treaty with England, Jay returned to his country. On arriving at New-York he was welcomed by a most enthusiastic public reception, and was presented by the corporation of New-York with the freedom of the city in a gold box. The office of Secretary for foreign affairs, which, for the want of a suitable incumbent, had been vacant for two years, was at this time urged by Congress upon his acceptance, and he did not feel at liberty to refuse his services. He was now virtually at the head of public affairs. The whole foreign correspondence of the government, the proposal of plans of treaties, instructions to ministers abroad, and the submission of reports on all matters to which Congress might call his attention, came within the scope of his new duties.