A GREAT NATIONAL SOCIETY FOR THE ADVANCEMENT OF LEARNING, is said to have been discussed recently at the meetings of inferior societies, and we have read a circular upon the subject, which contemplates a convention of scholars and men of letters, at Washington, some time in the coming winter. The American Philosophical Society, founded by Franklin, and made respectable by the labors of many eminent men, is no longer in authority, and its proceedings command little attention. The various societies for the cultivation of the natural sciences, in Philadelphia, Boston, and New York, are undoubtedly accomplishing much good, but the spheres and degrees of their influence would be greatly enlarged under a central organization. In such a design, the initiative should be taken by men of nerve as well as men of abilities, so that the dead weights of mediocrity so constantly obtruding into and making ridiculous the present societies, should be altogether excluded. Hitherto, in this city, the most reputable and dignified association connected with the advancement of learning, has been the Ethnological Society. It is to be feared that with the death of Mr. Gallatin, its president, and the dispersion of so many of its active members in the diplomatic service, its action hereafter will deserve less consideration than has thus far been awarded to it. LAMARTINE'S APOLOGY FOR HIS CONFIDENCES. Lamartine has just commenced the publication of a second part of his Confidences, in the feuilleton of _La Presse_, and precedes it by the following letter to the editor of that paper, which we translate for _The International_ from _La Presse_ of July 30. It relates to the way in which he came to publish the work, and gives a deeply interesting account of the pecuniary embarrassments under which he had for some time been laboring, and then eloquently defends the publication of what is real, and glowing in private life and experience. _To M. de Girardin:_