A LOYAL REGIMENT. – It is worthy of remark as somewhat more, perhaps, than a mere coincidence, that Major ROBERT ANDERSON, now in command of Fort Sumpter [Fort Sumter]; Lieut. A. J. SLEMMER, who within the walls of Fort Pickens, has defied the secession forces of Florida, Mississippi and Alabama ; Capt. J. B. RICKETTS, of Fort Brown, Texas, who has refused to surrender the post under his charge to the rebel authorities ; and Capt. BENNETT H. HILL, also of Texas, who has displayed true loyalty and courage, by refusing to obey the treasonable order of TWIGGS for the surrender of the Federal property under his charge, avowing his resolve to defend it to the last extremity and calling in reinforcements to aid him in doing so, - all belong to the First Regiment of the United States Artillery. As one of the best educated and most intelligent braches of the National military service, this loyalty on the part of the Artillery is not without significance. It speaks well for the morale of the whole regiment to find the four of its officers, who have been tried, thus proving themselves equal to the various emergencies of their respective situations and loyal to the banner of the Union.