The misfortune at Detroit was not, however, without a consoling effect. It was followed by signal proofs that the national spirit rises according to the pressure on it. The loss of an important post and of the brave men surrendered with it inspired everywhere new ardor and determination. In the States and districts least remote it was no sooner known than every citizen was ready to fly with his arms at once to protect his brethren against the blood-thirsty savages let loose by the enemy on an extensive frontier, and to convert a partial calamity into a source of invigorated efforts. This patriotic zeal, which it was necessary rather to limit than excite, has embodied an ample force from the States of Kentucky and Ohio and from parts of Pennsylvania and Virginia. It is placed, with the addition of a few regulars, under the command of Brigadier-General Harrison, who possesses the entire confidence of his fellow soldiers, among whom are citizens, some of them volunteers in the ranks, not less distinguished by their political stations than by their personal merits. The greater portion of this force is proceeding in relieving an important frontier post, and in several incidental operations against hostile tribes of savages, rendered indispensable by the subserviency into which they had been seduced by the enemy--a seduction the more cruel as it could not fail to impose a necessity of precautionary severities against those who yielded to it. At a recent date an attack was made on a post of the enemy near Niagara by a detachment of the regular and other forces under the command of Major-General Van Rensselaer, of the militia of the State of New York. The attack, it appears, was ordered in compliance with the ardor of the troops, who executed it with distinguished gallantry, and were for a time victorious; but not receiving the expected support, they were compelled to yield to reenforcements of British regulars and savages. Our loss has been considerable, and is deeply to be lamented. That of the enemy, less ascertained, will be the more felt, as it includes among the killed the commanding general, who was also the governor of the Province, and was sustained by veteran troops from unexperienced soldiers, who must daily improve in the duties of the field. Our expectation of gaining the command of the Lakes by the invasion of Canada from Detroit having been disappointed, measures were instantly taken to provide on them a naval force superior to that of the enemy. From the talents and activity of the officer charged with this object everything that can be done may be expected. Should the present season not admit of complete success, the progress made will insure for the next a naval ascendancy where it is essential to our permanent peace with and control over the savages.