Washington, Sunday Evening, May 5.  

Yesterday, Gen. Scott forwarded dispatches to Gen. Butler, at Annapolis, placing the Massachusetts Sixth Regiment and other troops at his command, and giving him three days to take possession of the Relay House, at the junction of the Baltimore and Ohio and Baltimore and Washington railways, nine miles from Baltimore and thirty from Washington. Butler responded that he would hold religious services there today. The Sixth Massachusetts Regiment went up early this morning. This movement is made to co-operate with the Pennsylvania troops now advancing upon Baltimore on the other side.