Mr. Sumner, Hon. C.F. Adams, and J.S. Eldridge, Esq., spoke in favor of the Resolutions; Hon. James T. Austin and William Harden, Esq., against them. They were finally laid on the table. The Whigs of Boston would not commit themselves to these principles. Mr. Sumner's name was placed at the head of the large delegation appointed by the meeting. The Convention assembled at Springfield, September 29, 1847, and organized with the following officers: Hon. George Ashmun, of Springfield, President; John C. Gray, of Boston, Thomas Emerson, of South Reading, James H. Duncan, of Haverhill, J.T. Buckingham, of Cambridge, Samuel Wood, of Grafton, James White, of Northfield, Theodore Hinsdale, of Litchfield, William Porter, of Lee, Truman Clark, of Walpole, John A. Shaw, of Bridgewater, and Samuel Osborn, of Edgartown. Vice-Presidents; John P. Putnam, of Boston, Linus B. Comins, of Roxbury, Charles R. Train, of Framingham, and S.H. Davis, of Westfield, Secretaries. Mr. Webster was present, and addressed the Convention, mainly on the Mexican War. Among the Resolutions adopted by the Convention was one recommending him as a candidate for President of the United States. While the Resolutions were pending, the following was moved as an amendment by Hon. John G. Palfrey. "_Resolved_, That the Whigs of Massachusetts will support no men for the offices of President and Vice-President but such as are known by their acts or declared opinions to be opposed to the extension of Slavery." This Resolution was the result of a conference among the more earnest Anti-Slavery members, with whom Mr. Sumner acted, in the hope of making opposition to the extension of Slavery a political test at the next Presidential election. It was sustained in speeches by Mr. Palfrey, Hon. C. F. Adams, Mr. Sumner, Hon. William Dwight, and Hon. Charles Allen, and was opposed by Hon. Robert C. Winthrop and Hon. John C. Gray. On the question being taken, the Resolution was declared lost. Mr. Sumner spoke as follows. Mr. President,--It is late, and I am sorry to trespass on unwilling attention. The importance of the cause is my apology. The question is, How shall we express our opposition to the extension of Slavery? Here it is satisfactory to know that there can be no embarrassment from constitutional scruples. It is not proposed to interfere with Slavery in any constitutional stronghold, or to touch any so-called compromise of the Constitution. Adopting the principle, so often declared by our Southern friends, that Slavery is a local institution, drawing its vitality from the municipal laws of the States in which it exists, we solemnly assert that the power of the Nation, of Congress, of the North as well as the South, shall not be employed for its extension, and that this curse shall not be planted in any territory hereafter acquired.