_15th._--An express from General Arnold, dated Trenton 14th, at six o'clock, received here at half past five this morning, says, that he had waited six hours, hoping to hear from General Sullivan, but had not; that he should immediately set off for Coryel's Ferry; that the reports of the country were, that the enemy were marching rapidly towards that place, and, that General Sullivan was about two miles ahead of them, on the same road. Coryel's Ferry is the place where our boats were stationed sufficient to transport 3000 men at a time. Another letter from General Arnold, dated _Coryel's Ferry_, 14th, 9 o'clock, P. M. received here at 9 this morning, says, that General Sullivan, arrived at that place about 4 o'clock, and had with him 1600 continental troops, and about the same number of Jersey militia making up the number already there about 4000; that the Jersey militia were turning out very spiritedly, and that he expected to be 5000 strong by the next day, when he should march towards the enemy, who had encamped at Somerset Court House, eight miles from Brunswick; that General Washington continued at his quarters near Middle Brook, eight miles in the rear of the enemy, who were about 7000. _16th._--The above makes up the chain of intelligence, to General Arnold's fourth letter, which was received here this morning, and is printed in the papers of the 17th and 18th inst., to which we refer you. From various quarters lately we have reports, but none sufficient to depend on, that the enemy will receive no reinforcement from Europe, and likewise that a war with France is inevitable. General Burgoyne is said to be arrived at Quebec with troops. We have seen a memorial, presented to the States-General by Sir Joseph Yorke, and two answers thereto, the one, "that they had no account to render to him of their conduct," the other, that "there are no gates to the Hague." We are, gentlemen, yours, &c. B. HARRISON, R. MORRIS, T. HAYWARD, J. LOVELL. * * * * * FROM THE COMMITTEE OF FOREIGN AFFAIRS TO THE COMMISSIONERS. Philadelphia, June 26th, 1777. Gentlemen, Since our last, of the 8th inst., in which you were informed of the enemy being encamped at Somerset Court House, eight miles from Brunswick, we have the pleasure of acquainting you, that on the 19th, at night, they made a precipitate retreat therefrom to the last mentioned place, and on the 22d decamped again, and wholly evacuated Brunswick, and retreated to Amboy. For particulars, we refer you to General Washington's letter to Congress, printed in the newspapers of the 25th inst.