DEAR SIR: I cannot lose a moment before acknowledging the receipt of your letter of the 29th ult., and of the valuable present which accompanies it--the two volumes of the new edition of Judge H. H. Brackenridge's "Modern Chivalry, or the Adventures of Captain Farrago and Teague O'Regan." My visit to Pittsburgh in 1843, and my intercourse with yourself, with the citizens of that place and Allegheny, at that time, afford me some of the most pleasing recollections of my life, grateful recollections of my obligations to yourself and them. I had read the first part of Modern Chivalry and formed a pleasant acquaintance with Captain Farrago and his man Teague, at their first appearance more than half a century since, and they had then excited much of my attention as illustrations of life and manners peculiar to the times and localities, not entirely effaced when I became more familiarly acquainted with them, by this visit to the latter. Captain Farrago and Teague O'Regan are legitimate descendants, on one side from the La Mancha and his squire Sancho, on the other, from Sir Hudibras and his man Ralph, and if not primitive conceptions themselves, are at least as lineal in their descent as the pious Æneas from the impetuous and vindictive son of Pelias. The reappearance of this work, as a second edition, since the author's death, more than half a century after its first publication, well warrants the prediction that it will last beyond the period fixed by the ancient statutes, for the canonization of poets, a full century. I shall read it over again, I have no doubt, with a refreshing revival of the pleasure with which I greeted it on its first appearance; and if this expression of my opinion can give any satisfaction to the remaining relatives of Judge Brackenridge, or to yourself, it is entirely at your disposal, being with a vivid sense and grateful remembrance of your kindness, and that of my fellow-citizens of Pittsburgh and Allegheny, Your friend and obedient servant, J. Q. ADAMS.