Dabixo Octbaues.—On last Friday evening, between the honrs of five and six o'clock, a son of Mr. W. H, Benson, of this city, and a negro servant, who had been sent with him, were attacked on the River road, near Man chester, whilst on their way from mill, by five armed negro men, clothed in the uniform of the United States army. The servant pleaded very hard for yonng Benson; bat, so far from lis