The military excitement in Philadelphia, Pa., continued. A large number of armed citizens were leaving for Harrisburgh.--The Mayor of Harrisburgh issued a proclamation, forbidding the citizens to leave town under penalty of arrest.
The rebel chief Porter, with about five hundred guerrillas, made a descent on Palmyra, Mo., this morning and released forty rebel prisoners. He held the town for a while, but withdrew when he heard an engine from Hannibal whistle. He did no damage whatever.--A force of rebel troops, under the command of Gen. Loring, took possession of the Kanawha salt-works, near Charleston, Va.--Richmond Dispatch, Sept. 20.
The rebels continued the attack upon the Union forces on Maryland Heights, who held the place until three o'clock, when an order was received to spike the guns and remove down the valley to Harper's Ferry.