PURCELLVILLE, October 28, 1862 - 6.30 p. m.

Two young men have been brought in by my pickets, who say they left Martinsburg last Thursday, and passed through Winchester; that all the rebel army was at Martinsburg, except Jackson, Longstreet, and Hill, who were at Winchester; that at Winchester they saw 2,500 men with small-pox, who were to be sent to Staunton; Stuart's two brigades of cavalry were at Berryville, between Winchester and Charlestown; that yesterday morning Walker's brigade was at Upperville; that this brigade had been picked from the whole rebel army. At Snickersville they saw one company of Second Virginia Cavalry and one piece of artillery, Shall send them, with other prisoners, to headquarters, to be examined.

My scouts captured a rebel signal-sergeant this afternoon, near the mountain.

A Union man told me to-day that Longstreet was at Upperville, and occupied Paris, Bloomfield, and Middleburg.

My people are not yet in from Aldie. A part of Stoneman's force is at Leesburg.

Very respectfully,

A. PLEASONTON,

Brigadier-General, &c.

General R. B. MARCY.

PURCELLVILLE, October 28, 1862 - 9 p. m.

My scouts are back from Aldie and Middleburg. No rebel troops at either place. about 100 paroled wounded and sick. A rebel doctor, in charge at Aldie, showed the officer an order of General Lee's dated at Winchester, October 27, directing him to remove the sick and wounded from Aldie and Middleburg to Winchester, and to impress wagons for their transportation. This my officer prohibited, and some of Sigel's cavalry coming up, he left them on picket there to prevent it.

Walker's brigade is between Upperville and Middleburg. The Georgia battalion of cavalry, some 800 strong, is at Union.

At Snickersville Gap there are two guns and a brigade of infantry in the mountains.

The roads are fine, and the country rolling and open about here.

In my dispatch of 6.30 p. m. I should have said Longstreet, Hill, and Jackson were at bunker Hill, instead of Winchester.

The cavalry driven out of Hillsborough yesterday was White's Independent Cavalry.

The rebel troops in this valley are evidently on foraging expeditions. The people generally are strong secesh.

Very respectfully,

A. PLEASONTON,

Brigadier-General,&c.

General MARCY.

PURCELLVILLE, October 28, 1862 - 9.30 p. m.

Numbers of the secessionists in this country are trying to send off their horses to the rebel cavalry, and, to prevent this, I have been obliged to take the horses for the Government service.