CINCINNATI, Tuesday, April 7, 1863.

The Commission met pursuant to adjournment. Members present, General Wallace, General Dana, General Tyler; also the judge-advocate and General Buell.

A communication from General Buell was read, desiring that the testimony of Lieutenant Fitzhugh might be taken as to the instructions that were sent to Major-General Thomas on the afternoon of the 8th of October.

After discussion it was decided in the affirmative.

Lieutenant C. L. FITZHUGH (a witness for the defense), being duly sworn by the judge-advocate, testified as follows:

By General BUELL:

Question. State your name and your position in the service of the United States; whether you were on duty with the Army of the Ohio at the battle of Perryville and in what capacity, if you please.

My name is Charles L. Fitzhugh; first lieutenant Fourth Artillery; aide-de-camp to General Buell. I was on duty at the battle of Perryville as an aide-de-camp.

Question. At what time was it first known at headquarters that a battle was raging on the left at Perryville on the 8th of October?

At about a quarter after 4 in the afternoon.

Question. Did you on that occasion carry any instructions to Major-General Thomas. If so, state what they were, whether you delivered them, and any circumstances of interest connected with your visit to General Thomas' headquarters.

One of General McCook's aides-de-camp came to our headquarters and reported the state of affairs on the left about a quarter past 4 in the afternoon. I was immediately ordered to ride over, with a guide who was at headquarters and who belonged on the right, and order an advance on the right at once, and "press the attack on the right"-those were the words of the order-as General McCook had been driven back on the left; also to order a brigade to move at once over to the Springfield road, which was the road we were encamped on. I left our camp about half past 4 with this guide, and we reached the right and found General Thomas out in front at about half past 6, as well as I can judge. It was about an hour after sundown. I gave him the orders. He asked me then if it was intended to advance that night after dark, and I repeated the order and left him to draw his own inference from the order, which was to advance at once. I came back with him to his headquarters, which were half a mile to the rear of the place where we then were, and took tea with him. When I was about to ride home again he told me to tell General Buell that the enemy were in strong force right in his front, and that an advance of 100 yards on his part would bring on an engagement along the whole line; but that he would advance the next morning at the first sound of an action on the left; that he would advance with the first gun; and he told me to ride over and report that to General Buell, which I did. I suppose the ride took me an hour and a half. I reached our camp about half past 9, and reported to General Buell. As I rode out to the front on my way over in the first place I met Brigadier General William S. Smith, who I believe commanded the advance division on the right in that corps. He said that the enemy were only a few hundred yards from him, and had thirty pieces of artillery in position right on his front. I told him that they had work on the left, and he said they would have harder on the right; that all the hard fighting was to be on the right. I reported that also to General Buell when I returned to camp.

General BUELL. I wish, Mr. President, to question the witness with reference to the circumstances of my visit to the camp of the First Division about the 23rd of August last.

The JUDGE-ADVOCATE. I shall object, Mr. President, to going into an examination of that.

General BUELL. I will explain more fully the object of this testimony. I except to show by this evidence the ground for the prejudice which