_September 2d._--Last night the whole encampment was thrown into the most intense excitement, by a row which broke out between two companies of Georgia troops, who were embarking on the steamer Corvette for Camargo. The combatants were principally Irish, and fought with their characteristic determination. Although we were some distance from the river, we could hear distinctly the blows, and demoniacal yells of the rioters, which were truly appalling. The conflict continued for two hours, during which several were killed, and wounded, and quite a number terribly bruised, and others were knocked overboard and perhaps drowned. Colonel Baker, of the 4th Illinois regiment, marched on board with twelve men, and demanded peace. He was himself attacked by four men with bayonets, which he warded off with his scabbard, at the same time defending himself with his sword, from the attack of the Irish captain, and succeeded in disabling him, by thrusting his sword into his mouth, and cutting open the whole side of his cheek. A savage yell was immediately heard from the mob, and the report of a pistol, which was aimed at the brave colonel’s head. He fell badly wounded, the ball entering the back of his neck, and coming out of his mouth. Then came the cry, “Help, your colonel is shot,--they have killed Colonel Baker.” This was too much, and we made a simultaneous rush for our arms. Colonel Bowles ordered out five companies, the Greys among the number,--and in five minutes we had a line formed around the boat, and the riot quelled, before the Illinois regiment had arrived. The exposure of last night has quite laid me up to-day, although the captain of the guard called me from the ranks, and sent me to my quarters long before morning. This has been a solemn day. We had two burials, and it is thought Colonel Baker will not recover. The whole day has been occupied in the court martial, which has resulted in sending the officers engaged in the riot, under arrest, to General Taylor, who is now at Camargo.