LOUISVILLE, January 21, 1863.

Commission met pursuant to adjournment. All the members present; also the judge-advocate and General Buell.

General ROUSSEAU'S testimony continued, as follows:

By General TYLER:

Question. General, in speaking yesterday of General Bragg's army you said "He had the best army for its numbers that I ever saw." Did you consider General Bragg's army at that time superior in its discipline and numbers to General Buell's army?

Yes, sir; I did consider it superior in discipline. I understand that he had a man shot every few days by his own orders. The principal reason why I think he had better discipline than we had in any of our armies was because I think he was seconded by his officers in a way perhaps that our generals were not and are not; I mean the subalterns. I did not consider it superior in numbers. That, however, is a mere guess of mine.

Question. General, give me your reasons for the fact that General Buell's army could not be brought to the same state of discipline that Bragg's army was?

In the first place, I understand all the officers who knew Bragg in the Army thought he was perhaps the best disciplinarian in the United States Army or among the very best. That is the universal opinion as far as I have heard, and I have conversed with a great many of the old Regular Army officers. In addition to that, I think the rebel officers, from the highest to the lowest, are more strict in the discharge of their duties than the subaltern officers of our Army, and that, I think, essential to the very existence of the Army in the rebellion, as it has been. I think that the want of discipline in our Army arises from the failure of subalterns to enforce it and to have breaches of discipline properly punished; and that is an evil that every sensible man who knows anything about the fact appreciates.

Question. General, whom do you consider directly responsible for the discipline of a regiment?

Of course the commanding officer.

Question. Who is responsible for the discipline of a company?

Of course the commanding officer, as far as his power and responsibility went, under the commanding officer of the regiment.

Question. Were you with General Buell's army at Corinth?

I was.

Question. Was the discipline of the army at or about the time of the battle of Perryville as good as it was at Corinth?

The discipline of General Buell's army proper was as good as it was at Corinth, and I am satisfied that the discipline of Buell's army was far better than that of any army I have ever seen, better drilled and better disciplined. When I speak of Buell's army proper I mean the troops under his immediate command at Corinth. General Mitchel's division was added to his army and a portion of it was Chaplin Hills.

Question. What portion of General Buell's army at Perryville was drawn from Mitchel's army and what was the discipline of that portion of the army?

I cannot now tell exactly what troops of Mitchel's division were at Perryville. I had a part of the Third Division there, with a brigade added to it at Nashville and three raw regiments at this place. I think several regiments of Mitchel's command were left at or in the vicinity of Nashville. In the main the discipline is what we would call god, though of some regiments the discipline was not good. Mitchel's division had been stationed in Alabama, and a good deal of feeling had been gotten up between citizens there and the men. Many of the men belonging to it were shot down by bushwhackers, or persons represented to be such, and, as we felt, murdered, and of course that tended to exasperate the soldiers and to cause breaches of discipline;