I have his verbal answer to-day, expressing great interest in the object of the memorial, but saying, that, beyond the revenue cutter, the Treasury Department has no vessel at Boston which can be detached on this service, and that the cutter was directed some weeks ago to do what it could for the relief of distressed vessels. Though the memorial was addressed to the Secretary of the Treasury, I felt it my duty to apply to the Secretary of the Navy. He entered into the plan with much benevolence, and expressed a desire to do all that the means at his command would permit. The only vessel at Boston in readiness is the steam-frigate Merrimack, which is about to start on a “trial-trip” of one week, previous to a cruise of six months. This vessel has already been ordered to make the week’s voyage direct from Boston to Norfolk; but the Secretary will give directions that she shall proceed to the Great Banks as far as can be judiciously done, under the circumstances, in order to afford relief to vessels in distress. He would extend the cruise to a longer term at once, but the contractors who have furnished her engines have certain rights which he is bound to respect. The Secretary authorizes me to say also that he will send further relief, if possible. I beg you to assure the memorialists that it will give me pleasure to promote the objects of the memorial to the full extent of my power. Believe me, dear Sir, faithfully yours, CHARLES SUMNER. JOHN T. SMITH, Esq., Exchange News-Room. THE EXAMPLE OF WASHINGTON AGAINST SLAVERY NOT TO BE FORGOTTEN NOW. LETTER TO A COMMITTEE OF THE BOSTON MERCANTILE LIBRARY ASSOCIATION, FEBRUARY 19, 1856. WASHINGTON, February 19, 1856. DEAR SIR,--I have been honored by your invitation to be with the Mercantile Library Association on the 22d instant. You know well the happiness I find in any coöperation with the young men of that Association, and I need not assure you of the gratification with which I should participate in any services calculated to exalt the example of Washington. Particularly at this moment should it be invoked, when the Republic, which he helped to found, seems to shake with the first throes of civil war, engendered by an interest which was condemned by him during life and formally abjured by him at his death. His great name should now be employed for the suppression of that Slave Power which is the fruitful mother of so much wretchedness. It will not be enough to quote his paternal words for Union: his example must be arrayed against the gigantic wrong which now disturbs this Union to its centre, and, in the madness of its tyranny, destroys the very objects of Union.