...Col. May.--On the Chickahominy River the rebels opened fire on the pickets of Gen. Sumner, but without any effect.--The rebel steam-tug Mark R. Chesk, was captured near Memphis, Tenn. The Paris Constitutionnel , of this day, published an article to show the impossibility of the South being conquered, and maintaining that foreign mediation alone will succeed in putting an end to a war disastrous to the inte...