The President and fellows of Middlebury College, and Norwich University, or either of them, may hereafter, with the assent and concurrence by vote of a majority of each of the nine Trustees elected, as aforesaid, and their successors, become incorporated and united with the corporation hereby created, by vote of their said corporations, at any meeting legally warned and holden, and by leaving for record, in the Office of the Secretary of State, a true and attested copy of such vote or votes, and of all the proceedings of the meeting or meetings, at which the votes aforesaid were passed, and causing the same to be recorded in the Office.