Our duty, brethren, is not to cavil over past grievances. Let us not be derelict to duty in the time of need. While we remember the past, and regret that our present position in the country is not such as to create within us that burning zeal and enthusiasm for the field of battle, which inspires other men in the full enjoyment of every civil and religious emolument, yet let us endeavor to hope for the future, and improve the present auspicious moment for creating anew our claims upon the justice and honor of the Republic; and, above all, let not the honor and glory achieved by our fathers be blasted or sullied by a want of true heroism among their sons. Let us, then, take up the sword, trusting in God, who will defend the right, remembering that these are other days than those of yore—that the world to-day is on the side of freedom and universal political equality. That the war-cry of the howling leaders of Secession and treason is, let us drive back the advance guard of civil and religious freedom; let us have more slave territory; let us build stronger the tyrant system of slavery in the great American Republic. Remember, too, that your very presence among the troops of the North would inspire your oppressed brethren of the South with zeal for the overthrow of the tyrant system, and confidence in the armies of the living God—the God of truth, justice, and equality to all men. With a knowledge of your zeal and patriotism, and a hope of its early development, I am yours, for God and humanity, A. M. GREEN. PHILADELPHIA, April 20, 1861. NEGROES IN THE SERVICE. From the Philadelphia Sunday Transcript, May, 1861. The colored portion of our population are anxious to do the State some service. Already they have organized one or more regiments, and are perfecting themselves in the drill. Among the documents which have already emanated from this branch of our population, as to the propriety of their engaging in such service, is the following from the pen of “Hamilcar,” a negro of more than ordinary ability. Without endorsing his communication we give it place, so that all sides may be heard: