Canada.

(From the Quebec Mercury.) Attack on Fort Schlosser. Head-quarters, Kingston, July 13.

By accounts from the army under Major-General De Rottenburg, dated the 9th instant, the following particulars have been received of a bold and successful attempt to surprise the American post at Fort Schlosser.

In the night of the 4th instant, a party, consisting of Volunteer Thompson and six privates of the 49th regiment, under Ensign Winder, and thirty-four of the militia, the whole under the command of Lieutenant Colonel Clarke, of the Lincoln militia, crossed over in boats from Chippawa to Fort Schlosser, which they reached a little before day-break, and completely surprised the guard, consisting of two Lieutenants, one serjeant, and eight privates, whom they made prisoners, together with three civilians and three of our own subjects, found in the Fort.– The party remained in the Fort about one hour, loading their boats form the public stores and wharf, and brought with them one brass six-pounder, 57 stand of arms, two and a half kegs of musket ball cartridges, 6 bulwarks of musket proof curtains for boats, one gun-boat, two batteaux, 20 barrels of salt, 17 casks tobacco, eight barrels of pork, and one barrel of whiskey, with a number of spades, oars, and axes ; a small party of the enemy had collected as the last boast pushed off from the shore, and several shots were fired, but the boats returned to Chippawa with their prisoners, and the articles they had captured, without a man being hurt on this service. Further accounts have also been received from the army highly creditable to the Indian warriors serving with it. On the 8th instant, a party of the King's regiment, and a body of Indian warriors were sent to endeavour to recover a considerable quantity of medicines and surgical instruments which had been buried near the Fort George when our troops retired from it. A skirmish ensued in consequence between the Indians and the enemy, in which the latter lost one officer and 20 men killed and 10 taken prisoners–the whole of the medicines and instruments were brought off by the party of the King's; the only loss sustained being three Indians wounded. Captain Norton led the Indian warriors with great spirit ; and much credit is due to Captain Merrit of the Provincial dragoons, for reconnoitering the spot where the medicines were deposited, and conducting the party to it.

A few nights ago, the barracks at Gravelly Point burnt by our gun-boats, and more than 100 barrels of pork, flour, and other articles brought away from thence, together with a very fine Durham boat–500 oars colleced and partly loaded in her for Sacket's Harbour, being destroyed.

Attack on Black Rock Head-quarters, Kingston, July 15 1813.

G. O.–His Excellency the Commander of the forces has received a dispatch from Major General De Rottenburg, reporting a successful attack upon the enemy's post and dockyard at Black Rock at daybreak on the morning of the 11th inst. by detachments of the King's and 41st regiments, together with Liutenant Fitzgibbon's party of the 49th, and about 40 militia, the whole amounting to 240 men, under the command of Lieutenant-Colonel Bishopp. The enemy's position was carried by a spirited attack without the loss of a single man. Several large boats, loaded with stores and provisions, and three field pieces, a twelve and two six-pounders, were brought away ; a vessel and all the naval store-houses and barracks have been burnt.

Unfortunately before the evacuation of the post was completed, a strong reinforcement of the enemy, aided by Indians, pressed this small detachment, by which Captain Saunders, of the 41st, and 15 men, were killed ; Lieutenant-Colonel Bishopp, Lieutenant Montpesson, of the 41st, and 15 rank and file, wound ed. The wounded were brought over.

Lieutenant-Colonel Bishopp has received three wounds, severe, but not considered dangerous.

By his Excellency's command,

Edward Baynes, Adjutant-General

British Expedition to Plattsburgh

The following is an extract of a letter from a respectable citizen at Burlington, dated Aug. 1. 1813

"An express arrived at Burlington on the 30th July, with intelligence that the British had left the Isle au Noix, with a force consisting of the two armed sloops, of 11 guns each, and four gallies, of one gun each, and 100 batteaux full of men, and had progressed within one mile of the town. The camp was instantly alarmed, and the troops under arms, but no enemy appeared. Next day we learnt that about 1000 troops, under the command of Colonel Murray, had landed, and took possession of Plattsburgh without opposition, there being no force to oppose them except the militia of the town and vicinity, who being only 400 in number, retreated as the enemy advanced. The arsenal belonging to the State, Pike's encampment, barracks at Serenac cantonment, and every building belonging to the United States, were immediately burnt. The enemy obtained both provisions and stores. The loss cannot be less than 50,000 dollars. The enemy left Plattsburgh on the 1st, and are understood to be proceeding this way  ??? ??? ??? ??? ??? ??? ??? ??? ??? On General Dearborn invading Canada, and taking possession of Fort George, he sent off to Greenbush, as prisoners of war, the following respectable inhabitants : Messrs Edwards, Murehead, Dickson Lyminston, Lawe, two Kerrs, M'Ewan, Parson Addison, Howell, Heron, Green, Baldwin, Clinch Jones, Ball, Decoe, and John Crook. Messrs Lawe, M'Ewen and the two Kerrs were wounded on the 27th June. General Dearborn expected that the inhabitants would have joined the Americans.

General Dearborn resigned the command of the Niagara army on the 23th June, on account of indisposition. General Lewis says, in his dispatch to Secretary at War, that he did not think the General would ever again be fit for service ; that the unfortunate events of the war had deranged his understanding ; and that thought sometimes in a state of convalescence, he uniformly relapsed when military topics were alluded to. General Lewis having been nominated to command at Sacket's Harbour, is succeeded at Fort George, Niagara, and on the Canadian frontier, by General Boyd.

The Indian chief, Tecumseh, has seized the favourable moment of the diversion by our shipping in Virginia, for surround Fort Meigs with 2000 warriors. He had deprived the garrison of all the possibility of receiving supplies. General Clay, who commanded there, had written urgently to General Harrison for assistance. The latter was collecting his army to march to his relief.

Sir James Yeo, after the retreat of the enemy's army at Fort George, swept the American side of Lake Ontario. He landed a body of troops at Great Sodus, and took the whole of the provisions, consisting of several hundred barrels of pork and flour, and burnt the buildings. The British loss was a serjeant and four privates of the Royal killed. At Genessee River, he inflicted the same loss on the enemy, taking 500 barrels of pork and 1700 bushels of corn. The provisions were delivered to General Vincent. Four companies of the Royals were embarked on board the fleet, to serve as mariners

There were at Quebec, on the 22d July, 1000 American prisoners of war, captured since the commencement of the campaign. At Beaufort there were 50 officers including three General. In consequence of the conduct of the American Government and of the officers, the latter are no longer permitted to return home on parole. The Melpomene frigate, with De Meuron's regiment, from the Mediterranean, arrived in the river St. Lawrence on the 20th July.

James Gready, private in the 8th, or King's regiment, and Terence Hunt, private in the 6th foot, were in the latter end of June, tried by Court Martials, for deserting to the enemy, and being found in arms, and were publicy shot at Kingston, Canada, pursuant to their sentence.

It appears from the Quebec papers, and from the general orders issued by the Commander in Chief in Canada that on the late defeat of General Wilkinson on the banks of the Miami river, the American military chest, containing 15,000l. Sterling was among the property captured by the British.

Captain Waugh, of the 103d regiment, died at Chamely on the 2d July.

General Hampton has arrested Colonel Clark, the late commandant at Burlington, for a defalcation of about 50,000 dollars.

