The one power that has legs long enough and strong enough to wade across the Potomac offers itself at this hour; the one strong enough to bring all the civility up to the height of that which is best, prays now at the door of Congress for leave to move. Emancipation is the demand of civilization. That is a principle; everything else is an intrigue. This is a progressive policy, puts the whole people in healthy, productive, amiable position, puts every man in the South in just and natural relations with every man in the North, laborer with laborer. I shall not attempt to unfold the details of the project of emancipation. It has been stated with great ability by several of its leading advocates. I will only advert to some leading points of the argument, at the risk of repeating the reasons of others. The war is welcome to the Southerner; a chivalrous sport to him, like hunting, and suits his semi-civilized condition. On the climbing scale of progress, he is just up to war, and has never appeared to such advantage as in the last twelvemonth. It does not suit us. We are advanced some ages on the war-state,—to trade, art and general cultivation. His laborer works for him at home, so that he loses no labor by the war. All our soldiers are laborers; so that the South, with its inferior numbers, is almost on a footing in effective war-population with the North. Again, as long as we fight without any affirmative step taken by the government, any word intimating forfeiture in the rebel states of their old privileges under the law, they and we fight on the same side, for slavery. Again, if we conquer the enemy,—what then? We shall still have to keep him under, and it will cost as much to hold him down as it did to get him down. Then comes the summer, and the fever will drive the soldiers home; next winter we must begin at the beginning, and conquer him over again. What use then to take a fort, or a privateer, or get possession of an inlet, or to capture a regiment of rebels? But one weapon we hold which is sure. Congress can, by edict, as a part of the military defence which it is the duty of Congress to provide, abolish slavery, and pay for such slaves as we ought to pay for. Then the slaves near our armies will come to us; those in the interior will know in a week what their rights are, and will, where opportunity offers, prepare to take them. Instantly, the armies that now confront you must run home to protect their estates, and must stay there, and your enemies will disappear.