HEADQUARTERS ARMY OF THE POTOMAC, June 1, 1863.

Major General H. W. HALLECK,
General-in-Chief:

The following is received from General Buford, at Warrenton Junction, to-day:

A reconnaissance returned late yesterday, satisfying me that there are no rebel troops on this side of the river, save those who have been here all winter. Sulphur Springs, Waterloo, and Orleans were visited yesterday. Another command penetrated as far as Gainesville, returning by New Baltimore and Warrenton. Nothing was heard except that some small particles belonging to Mosby were seen by negroes a few days since. Mosby has three companies, and his headquarters are supposed to be somewhere in Loudoun County.

DANL. BUTTERFIELD,

Major-General.

CAMP NEAR FALMOUTH, VA., June 1, 1863.

Commanding Officer, Fifth Corps:

The major-general commanding directs me to acknowledge the receipt of your communication date May 31, 9 p. m., inclosing one news-paper, dispatch from General Barnes, and note received by the commanding officer of the pickets at Kelly's Ford.

I am directed to say that all correspondence of the enemy is to be forwarded to headquarters, and no answers returned except from headquarters. The correspondence received seems evidently to have been ordered for the purpose of getting information concerning our presence and purposes in that vicinity. General Barnes seems to have divined the purpose of the enemy in this correspondence, and to have treated it properly. No person can be allowed to enter our lines except by permission of the Secretary of War.

The letter states that two newspapers were received; but one has been forwarded to these headquarters. Attention is called to Paragraph I, General Orders, Numbers 40, April 10.

A cavalry force, sufficient to replace that withdrawn by Colonel Duffie, will be ordered either from the troops stationed here, or from General Buford's command, and be directed to report to General Barnes, at Grove Church.

It is not deemed advisable at present to move the Second Division of your corps from its camp. The difficulty of supplying artillery renders it inexpedient to send it on this service without further developments. It is presumed that the force now on duty will be vigilant in the performance of their duties. It will be active in obtaining and sending in information, so that any movements of the enemy may be promptly reported at headquarters.

Very resepctfully, &c.,

DANL. BUTTERFIELD,

Major-General, Chief of Staff.

HEADQUARTERS CAVALRY CORPS, June 1, 1863.

Brigadier-General MEIGS,

Quartermaster-Genera, Washington:

A good many young horses three and four years old are sent to the cavalry. No cavalry horse should be under six years of age. Cannot this be remedied by inspection at Washington?

36 R R-VOL XXV, PT II