department. The medical director will give them such instructions as are necessary for the performance of their duties.

II. Brigadier Surg. George Suckley will proceed to Wheeling, Va., and relieve Asst. Surg. W. A. Hammond in the duties of medical purveyor in this department.

* * * * * *

By command of Major-General Rosecrans:

GEO. L. HARTSUFF,

Assistant Adjutant-General.

[12.]

SPECIAL ORDERS,
HDQRS. ARMY OF THE POTOMAC, No. 89.
Near Alexandria Seminary, March 23, 1862.

* * * * * *

4. In pursuance of instructions from the Secretary of War, Brigadier General Thomas A. Davies is relieved from duty with this army and will without delay report to Major General H. W. Halleck, commanding the Department of the Mississippi.

* * * * * *

10. Brigadier General M. R. Patrick, volunteer service, is assigned to duty with King's division, First Corps, and will report accordingly without delay.

By command of Major-General McClellan:

S. WILLIAMS,
Assistant Adjutant-General.

[12.]

SPECIAL ORDERS,
HDQRS. ARMY OF THE POTOMAC, No. 90.
Near Alexandria Seminary, va., March 24, 1862.

* * * * * *

2. The cavalry serving with this army is assigned to duty as follows: To the First Army Corps, McDowell's: Second New York Cavalry, Colonel J. M. Davies; First New York Cavalry, Colonel McReynolds; Brigadier General J. P. Hatch to have command of the cavalry serving with the First Army Corps. To the Second Army Corps, Sumner's: Third New York Cavalry, Colonel Van Allen; Eighth Illinois Cavalry, Colonel Farnsworth, heretofore serving with Hamiltonn's division, Third Corps; one squadron of the Sixth New York Cavalry, Colonel Devin. Brigadier General ---- ---- will report to General Sumner for the command of the cavalry serving with his corps. To the Third Army Corps, Heintzelman's: Third Pennsylvania Cavalry, Colonel Averell; First New Jersey Cavalry, Colonel Wyndham. To the Fourth Corps, Keyes': First Pennsylvania Cavalry, Colonel Bayard, now serving with McCall's division, First Corps; Fifth Pennsylvania Cavalry (late Friedman's); Fourth New York Cavalry, Colonel Dickel, now serving with Blenker's division, Second Corps. To the Fifth Corps, Banks': Fifth New York Cavalry, Colonel De Forest; First Vermount Cavalry, Colonel Holliday; First Michigan Cavalry, Colonel Brodhead; First New England Cavalry, Colonel Lawton; First Maine Cavalry, Colonel Allen; the Maryland cavalry (eighteen companies); the battalion of Pennsylvania cavalry and the squadron of Virginia cavalry now with Shields' division. The Cavalry Reserve will be commanded by Brigadier General P. St. George Cooke, U. S. Army, and will consist of two brigades, as follows: First Brigade, to be commanded by Brigadier General W. H. Emory: Fifth U. S. Cavalry, Sixth U. S. Cavalry, Sixth Pennsylvania Cavalry, Colonel Rush. Second Brigade, to be commanded by Colonel George A. H. Blake, First