"MY DEAR SIR,--Many of our Free-Territory men in this quarter are in doubt as to the course which the New York Democracy intend to pursue in reference to the Buffalo convention. Will they be represented in it? Will they concur in the nominations made by it? If Judge McLean can be induced to accept a nomination for the Vice-Presidency, in connection with Mr. Van Buren for the Presidency, will they cordially accept it? If the convention, on mature deliberation, should think it expedient to nominate Judge McLean for the Presidency and Col. Samuel Young or Bradford R. Wood or yourself for the Vice-Presidency, would the New York Democracy concur in that nomination? There is a strong disposition, also, in the West to drop the older politicians altogether and take younger men, who better represent the spirit of the time. One of the best and ablest Democrats in the State, I mean Edwin M. Stanton, said to me to-day that if John Van Buren should be the nominee of the Buffalo convention he would roll up his sleeves and go to work till the election for the ticket; and I am sure that to all the young Democrats and all the young Whigs in the State your name would be more acceptable than your father's. Suppose the convention should be animated by this spirit and nominate men of this generation, would the New York Democracy concur? "I put these questions to indicate the various phases which the movement may assume. My own opinion is that, under existing circumstances, the best possible nomination for the Presidency has been made at Utica, provided the name of John McLean can be associated with it. Whether it can be is, as yet, in doubt, though I fear the doubt will be resolved against my wish. If it cannot be, we have no man in the West whose name on the ticket would be altogether unexceptionable. If Judge McLean should consent to allow his name to be used, the ticket would undoubtedly sweep Ohio, and would gain immense accessions of strength throughout the West. I firmly believe that the nominees may, in that event, be elected this year. It would be, to be sure, sacrificing a good deal on the part of Judge McLean, so long prominent in the regards of the people as a candidate for the first office, to accept a nomination for the second; and the bitterness with which he could be assailed by the slaveholders and their allies would exceed greatly that which is now manifested towards your father. Nothing but a strong sense of personal duty, and a deep interest in the success of the movement (and he avows that interest openly), will prevail on him to consent, and, I fear, he will not feel that duty absolutely requires the step. It is probable that he would regard an offer of a nomination for the first office differently. He would then be the recognized head or representative of the movement, and would feel the abuse directed against him, as levelled chiefly at the cause. And I think he would represent the movement almost exactly as Silas Wright would have done