Colonel Montgomery was Lieutenant-Colonel of the ninth regiment of foot, son of Sir Robert Montgomery, of Ireland, and half-brother of Mrs. George Byng, and the Marchioness Townshend. He was a remarkably handsome man, and he had, also, fought bravely in the service of his country. In the Dutch expedition, the Russians being put to flight, his regiment was thrown into confusion, and retreated, in consequence of the Russians falling back upon them. At this time a drummer was killed, and Colonel Montgomery took up the drum, beating it to rally his men, he himself standing alone. He succeeded in rallying them, and at their head rendered essential service. On several occasions, in Egypt and Malta also, he had distinguished himself by his courage and spirit. He was very intimate with the Prince of Wales and the Duke of York. The former shed tears on being apprised of the melancholy end of his friend. Colonel Montgomery was well known in London by the _sobriquet_ of the Duke of Hamilton’s _double_, from his studiously copying that nobleman’s style of dress. Captain Macnamara recovered of his wound, and was tried for murder. His defence, which was prepared by Lord Erskine (then Mr. Erskine), stated:—“I am a captain of the British navy. My character you can hear only from others. But to maintain my character in that situation I must be respected. When called upon to lead others into honourable danger, I must not be supposed to be a man who sought safety by submitting to what custom has taught others to consider as a disgrace. I am not presuming to urge anything against the law of God, or of this land. I know, that in the eyes of duty and reason, obedience to the law, though against the feelings of the world, is the first duty, and ought to be the rule of action; but upon putting a construction upon my motives, so as to ascertain the quality of my actions, you will make allowance for my situation. It is impossible to define in terms the proper feelings of a gentleman; but their existence has supported this country for many ages, and she might perish if they were lost.” April 15. Yesterday morning Mr. Heaviside, the surgeon, was arrested by Townsend, under authority of a warrant from Sir Richard Ford, wherein he stands charged with having been aiding and assisting in the murder of Colonel Montgomery; and, after undergoing a private examination before the above magistrate, at Bow Street, he was fully committed to Newgate for trial, at the ensuing Old Bailey Sessions. Several witnesses were also privately examined respecting the duel, and bound over to appear on the trial. Captain Macnamara was yesterday declared out of danger, but was not yet well enough to be removed. The coroner’s inquest, on taking a view of the body of Colonel Montgomery, brought in a verdict of “manslaughter.” The remains were buried in a vault in St. James’s Church.