The War on the Potomac.
Saturday night's dispatches brought us cheering news, that Gen. Pope had met the main body of the enemy at Gainesville, on the Manassas road, and after a bloody battle, lasting all day on Friday, the enemy were routed, and were on retreat through the Blue Ridge passes. In this fight Gen. Pope reports his loss at 8,000, and the enemy's double that number. But the news of last night is of a less favorable character. The enemy returned on Saturday, reinforced with overwhelming numbers, and our army was forced back, after terrible conflict, to Centreville, where it was joined by the columns of Sumner and Franklin, and made a stand. During yesterday there was but little fighting, our army being reported in strong position and in good spirits and fighting trim.
The divisions of Pope, McClellan and Burnside are reported to be in position of effective co-operation, and that, though Gen. Banks' force is cut off, the utmost confidence is entertained at Washington that success will crown the Union arms in a short time.
The public anxiety, before intense, is now wrought to a painful pitch. We trust that it will be relieved by the next dispatches, confirming the hopes reported to be entertained at headquarters in Washington.