From the Southwest.
A gentleman who recently left Vicksburg informs the Petersburg Express that our troops at that point are in excellent spirits, and the Generals commanding feel the utmost confidence in their ability to repel any attack of the enemy, either by land or water, whether it come in moderate or extraordinary force. This gentleman met several trains of the Yankee prisoners' captured at Murfreesboro', en route for Vicksburg. They had been paroled, but not exchanged. Participants in the fight near Murfreesboro' say that our army retired to Tullahoma in perfect order, and brought with them everything of value. The prisoners, cannon, and small arms captured were all brought off safely. The prisoners represent that the slaughter of their army was really appalling, exceeding anything that has been witnessed since the war commenced.Gen. Bragg left Murfreesboro' because the whole country was exhausted of supplies for man and blast. At Tullahoma supplies are ample, the water good, and the topography of the country more favorable to successful defence than almost any other point in Middle Tennessee.
