HEADQUARTERS FOURTH CORPS, July 6, 1863 - 1. 15 p. m.

Major-General DIX,
Commanding Department of Virginia:

GENERAL: My cavalry scouts report a body of the enemy's cavalry and infantry at Tunstall's Station. Thus they are reported as being present in four directions, and it is possible they meditate an attack. It is my opinion that there are more of the enemy in my neighborhood than is generally supposed. If attacked on my right, I request that you will direct General Gordon or Spinola to press up to my support, between here and the railroad.

E. D. KEYES,

Major-General.

HEADQUARTERS FOURTH CORPS, Camp near Baltimore Store, Va., July 6, 1863 - 2. 30 p. m.

Major-General DIX,

Commanding Department of Virginia, White House:

GENERAL: I have to acknowledge the receipt of your note of yesterday's date. I regret as much as ; you do that the move to Bottom's Bridge was not accomplished. All testimony corroborates the correctness of our decision that another brigade was necessary. As soon as our advance became known, the enemy began to re-enforce on this side the Chickahominy. A contraband saw a solid column of infantry, reaching from the bridge to this side the house we used last summer as a hospital. They crossed artillery and more infantry early in the morning of the 2d, and I have every reason to believe they brought a force greater than my own up to Baltimore Cross-Roads, where they attacked on the evening of the 2d. Lieutenant-Colonel [Samuel H.] Roberts (New York), in command of our skirmishers, declared that, which was the fact. With our very imperfect knowledge of the roads and paths between the Cross-Roads and the bridge, and their perfect knowledge of these, a much superior force was necessary to render success probable. As you forbade us to destroy the bridges, the object of diverting a force from Getty was accomplished by keeping it a long way this side the river. The waste of gunpowder on the night of the 2nd was not by our side, but by the rebels. My main line did not fire a shot. The subordinate line, perpendicular to the main line, intended as a decoy, was so arranged that the enemy, though so near as to be heard urging their men on, poured out their fire three or four hours without injury, which was owing to good luck or good management. They ceased firing on the morning of the 3d, which was the time I was expected to return. I certainly succeeded in diverting a large force from Getty as long as it was anticipated would be necessary. Yesterday I sent a scouting party down to Long Bridge. That bridge has been destroyed since I have been here. The enemy have a strong force, and a breastwork on the other side. Two of our cavalrymen were wounded yesterday. Our casualties since leaving White House, on the 1st instant,