...exas, will join Gen. McCulloch in a few days.--Also, one regiment from Mississippi, and one from South, Carolina. The Constitutional, of Alexandria, Louisiana, has information direct from Mesilla , which states that on 5th inst. Gen. Johnston was at Picach, about five miles north of Mesilla, in command of the Confederate forces, which command, tendered by Lieut, Col. Baylor, the General had a...