The correspondence thus begun, was carried on be tween Arnold and Major André, Adjutant General to the British army, in behalf of Sir Henry Clinton, under feigned signatures, and in a mercantile disguise. In an intercepted letter of Arnold, which lately fell into our hands, he proposes an interview to settle the risks and profit of the copartnership, and in the same style of metaphor intimates an expected augmentation of the garrison, and speaks of it as the means of extending their traffic. It appears by another letter, that André was to have met him on the lines, under the sanction of a ﬂag, in the character of Mr. John Anderson. But some cause or other, not known, prevented this inter view. The twentieth of last month, Robinson and André went up the river in the Vulture sloop of war. Robin son sent a ﬂag to Arnold with two letters, one to Gen eral Putnam, enclosed in another to himself, proposing an interview with Putnam, or in his absence with Ar nold, to adjust some private concerns. The one to General Putnam was evidently meant as a cover to the other, in case, by accident, the letters should have fallen under the inspection of a third person.