OFFICE COMMISSARY-GENERAL OF PRISONERS,

Washington, D. C., May 18, 1863.

Lieutenant Colonel W. H. LUDLOW,

Agent for Exchange of Prisoners, Fort Monroe, Va.

COLONEL: Your letters of the 14th, 16th and 17th instant and also several telegrams relating to the delivery of individual prisoners of war are in our hands. After many applications I have succeeded in getting a report in the case of Captain Baylor, and as it is represented that there is testimony to prove that he fired upon a flag of truce and caused the death of one of our men an order has been issued of his immediate trial.

Colonel Morehead, Doctor Dixon, Captain or Lieutenant James H. Baker and Private John W. Garrett, Company D, First Kentucky Infantry, at Johnson's Island, and Captain David Lynn, at Fort Delaware, are ordered to be delivered for exchange immediately. The Secretary of War has not yet decided to order the delivery of Colonel Poindexter. Major Sauders is at Fort Lafayette at the disposal of the Navy Department.

I am unable to find the name of Arnold Harris, Jr., on any of our books. Thomas Tait Tunstall was released some time since on his pledge to remain abroad during the war. Clagett D. Fitzhught and George M. Shearer are in the Old Capitol Prisin. The former denies that he is an officer in the rebel army. Says he is only a private. The latter says he was a lieutenant but is not now in the army. Both cases are held for the action of the War Department.

I did not know of the presence of the twelve men of Mosby's cavalry at the Old Capitol Prison till I received your telegram. Unless they are held for trial for some offense outside of their duty as soldiers they will be sent down on the State of Maine. I some days since obtained authority from the General-in-Chief to direct that in all cases where prisoners were arrested charged as spies or with any other act cognizable by a military tribunal they should be brought to immediate trial. This will prevent the great wrong of holding prisoners for months on charges which have little or no foundation. I have again and again ordered that all prisoners of war in our possession, including all irregular organizations, not spies, should be sent forward for delivery or exchange, and when it has not been done it has been from some obstacle not known or reported to me. Such things, however, are not done with a view to evade our obligations, but are thought to be necessary from some peculiar circumstances in the individual cases.

The two women sent down by the steamer on her last trip to whom Mr. Ould refers were not arrested nor sent forward on account of their personal character but for serious acts of disloyalty, being confirmed rebels, and it was not to be expected that in their position in life their morals could be very correct; nor was that examined into. They were sent South simply because they were determined to give the rebellion all the aid in their power. For their grossly outrageous conduct on the boat they should have been properly disposed of and punished on board the steamer, and certainly their obscene language should not have been permitted to reach the ears of ladies.

I will write to General Banks on the subject of exchanged prisoners and prisoners of irregular organizations as you request. I have not written to General Rosecrans about the canceling of oath of allegiance taken by persons in Kentucky and Tennessee on either side of the line by way of an exchange as you suggested was desired by Mr. Ould because I do not think the Government could admit so formally that