The Negroes at Washington.A gentleman recently from Washington, D. C., brings information to the Examiner, that the stolen and runaway negroes from Virginia to the number of three thousand and upwards, are encamped on the “Slashes,” within the northern precincts of the city. They are badly clothed, worse fed, and their scanty tents furnish but a poor shelter from the warring elements at this inclement season. Many have died, and numbers are dying every day from pneumonia and typhoid diseases,induced by their exposed condition, and the emaciated state of the survivor ; aud the squalor and filth pervading the encampment, beggar all description. The efforts to procure employmont for those who are able and willing to work have been ineffectual, as the menial places about the Government Departments' are filled by hungry Yankees and housekeepers, who refuse to hire the “runaways,” even when offered for their vituals and clothes. In view of Abraham Lincoln’s recent emancipation proclamation, well may the blacks of theSouth enquire: “Is this the entertainment to which we are invited ?”—Peters. Express.