The play of Othello without the part of Othello would be a barren spectacle; and the example of Washington, without his testimony against the malevolent force which disturbs the Republic, would be hardly less barren. Let the young men of Boston be encouraged to dwell on those sentiments and acts which, while they elevate his name, apply with prevailing power to the existing state of things among us. Let them bear in mind that he declared it to be “_among his first wishes_ to see some plan adopted by which Slavery in this country may be _abolished by law_,”--that, to promote this purpose, he expressed a desire, in a recorded interview with a distinguished foreigner, for the formation of an Antislavery Society,--that on many occasions he condemned Slavery,--that, in congratulations to Lafayette on his purchase of a plantation with a view of emancipating the slaves on it, he exclaimed, “Would to God a like spirit might diffuse itself generally into the minds of the people of this country!”--and that, finally, by his last will and testament, written within six months of his death, he bore his practical testimony to those ideas and aspirations, by the emancipation of his slaves. With these things taken to heart, the example of Washington will exert its just conservative influence over the country, holding it back from the extension of that evil against which he set himself, and arousing the general sentiment to repulse the aggressions which now threaten civil war. Then, indeed, will the Father of his Country have a new birth and influence. Believe me, my dear Sir, very faithfully yours, CHARLES SUMNER. CHARLES G. CHASE, Esq., &c., &c., &c. CONSTANT EXERTION AND UNION AMONG GOOD MEN. LETTER TO A MASSACHUSETTS COMMITTEE, FEBRUARY 25, 1856. The papers announce, that the following letter, when read, was received with six rousing cheers. SENATE CHAMBER, February 25, 1856. MY DEAR SIR,--I cannot be present at the festival in commemoration of the election of Mr. Banks as Speaker. My duties will keep me here. But with you I rejoice in this triumph of Freedom, which is the first achieved in the National Government, since the recognition, by the earliest Congress under Washington, of the Ordinance prohibiting Slavery in the Northwestern Territory. To advance this victory, and to obtain its just fruits, there must be no relaxation of efforts, but constant exertion, with union among good men, and a determination to yield no jot in the conflict. To Massachusetts belongs an honorable place at the head of the battle. May no treason or hesitation of any of her sons deprive her of this post! Yours, faithfully, CHARLES SUMNER. F. H. UNDERWOOD, Secretary, &c., &c. THE ABROGATION OF TREATIES. SPEECHES IN THE SENATE, MARCH 6 AND MAY 8, 1856.