Jay's suspicions concerning the French minister happened now to receive opportune corroboration. On September 4 Rayneval, secretary to de Vergennes, had a long interview with Jay concerning boundaries, in which he argued strongly against the American claims to the western lands lying between the Alleghanies and the Mississippi. This touched Jay nearly, for the navigation of the Mississippi was the one object which he had especially at heart. Six days later the famous letter of Marbois, de la Luzerne's secretary, which had been captured _en route_ from Philadelphia to de Vergennes at Paris, was put into the hands of Jay through the instrumentality of the English cabinet. This outlined a scheme for a secret understanding between England and France to deprive the Americans of the Newfoundland fisheries. This evidence seemed to prove Jay's case; yet Franklin remained strangely unshaken by it, for he reflected that it came from the British ministry and was infected with suspicion by this channel. But still another occurrence came to strengthen Jay's conviction of some latent hostility in the French policy, for he learned that Rayneval was making a rapid and secret journey to London. He felt sure that this errand was to intimate to Shelburne that France did not incline to support the demands of her American allies. In the fullness of his faith he took a courageous, very unconventional, but eminently successful step. He persuaded Vaughan to hasten to London, and to present sundry strong arguments going to show that it was the true policy of England to grant the demands of the States rather than to fall in with the subtle plans of France. He felt with regret that he could not consult Franklin regarding this proceeding, which he undertook upon his own sole responsibility. It put Shelburne in a singular position, as arbiter between two nations enemies of England and allies of each other, but each manoeuvring to secure its own advantage at the cost of its friend, and to that end presuming to advise him upon English interests. He did not ponder long before accepting the American arguments as the better, and deciding that the English policy was rather to be liberal towards a kindred people than to unite with a traditional foe in curtailing their prosperity. He said to Vaughan: "Is the new commission necessary?" "It is," replied Vaughan; and his lordship at once gave orders for making it out. Had he fallen in with the French ideas, he would, upon the contrary, have cherished this disagreement for a while, in order finally to sell out a concession on this point at the price of some such substantial matter as the fisheries or the western lands. Forthwith Vaughan was on his way back to Paris, accompanied by a messenger who carried the amended document empowering Oswald to treat with the commissioners of the "Thirteen United States of America, viz.: New Hampshire," etc., naming them all. "We have put the