Copy of a letter from Major Gen. Brown, to Gen. Armstrong, Secretary of War. “HEAD QUARTERS, FORT ERIE, 20th September, 1814. “SIR—Among the officers lost to this army, in the battle of Niagara Falls, was my aid-de-camp, Captain Ambrose Spencer, who being mortally wounded, was obliged to be left in the hands of the enemy. By flags from the British army, I was shortly afterwards assured of his convalescence, and an offer was made me by Lieutenant General Drummond, to exchange him for his own aid, Captain Loring, then a prisoner of war with us. However singular this proposition appeared, as Captain Loring was not wounded, nor had received the slightest injury, I was willing to comply with it on Captain Spencer’s account. But as I knew his wounds were severe, I first sent to ascertain the fact of his being then living. My messenger, with a flag, was detained, nor even once permitted to see Captain Spencer, though in his immediate vicinity. “The evidence I wished to acquire failed; but my regard for Captain Spencer, would not permit me longer to delay, and I informed General Drummond, that his aid should be exchanged, even for the _body_ of mine. This offer was, no doubt, gladly accepted, and the _corpse_ of Captain Spencer sent to the American shore.” * * * * * _Note to MONTREAL._—The custom of emblazoning on the flags, and other military insignia of the regiments, the actions in which they have signalized themselves, obtaining in the British and other European services, is not now allowed in that of the United States, on the score of its aristocratic tendency! Although, perhaps, in the instance alluded to, the stupidity of the individual prevented him from understanding their meaning; still, to the more intelligent of the soldiers, they are no doubt a great incentive to uphold the honour of the regiment. * * * * *