Let this bill pass, and then will be accomplished the first practical triumph of Freedom, for which good men have longed, dying without the sight,--for which a whole generation has petitioned, and for which orators and statesmen have pleaded. Slavery will be banished from the national capital. This metropolis, bearing a venerated name, will be exalted, its evil spirit cast out, its shame removed, its society refined, its courts made just, its revolting ordinances swept away, and even its loyalty assured. If not moved by justice to the slave, then be willing to act for your own good and in self-defence. If you hesitate to pass this bill for the blacks, then pass it for the whites. Nothing is clearer than that the degradation of Slavery affects the master as well as the slave; while also recent events testify, that, wherever Slavery exists, there Treason lurks, if it does not flaunt. From the beginning of this Rebellion, Slavery has been constantly manifest in the conduct of the masters, and even here in the national capital it is the traitorous power encouraging and strengthening the enemy. This power must be suppressed at every cost; and if its suppression here endangers Slavery elsewhere, there will be new motive for determined action. Amidst all present solicitudes, the future cannot be doubtful. At the national capital Slavery will give way to Freedom. But the good work will not stop here: it must proceed. What God and Nature decree Rebellion cannot arrest. And as the whole wide-spread tyranny begins to tumble, then, above the din of battle, sounding from the sea and echoing along the land, above even the exultations of victory on hard-fought fields, will ascend voices of gladness and benediction, swelling from generous hearts, wherever civilization bears sway, to commemorate a sacred triumph, whose trophies, instead of tattered banners, are ransomed slaves. REBEL BARBARITIES, AND THE BARBARISM OF SLAVERY. RESOLUTION AND REMARKS IN THE SENATE, APRIL 1, 1862. Mr. Sumner offered the following resolution, and then spoke upon it. “_Resolved_, That the Select Committee on the Conduct of the War be directed to collect the evidence with regard to the barbarous treatment by the Rebels at Manassas of the remains of officers and soldiers of the United States killed in battle there, and to report the same to the Senate, with power to send for persons and papers.” MR. PRESIDENT,--We have all been shocked, during the last few days, by the evidence that has accumulated with regard to the treatment of our dead at Manassas.