Henry James was a prolific and prolix letter-writer. Many of us James addicts must have assumed, when Leon Edel had completed his magisterial labours - not only a multi-volume biography of the Master, but four stout door-stoppers of letters - that the world had seen the last scrapings of the James barrel. Basta, pure basta! as Henry James himself exclaimed in August 1908 to William Dean Howells, one of his oldest family friends, about the near completion of the 23- volume (disastrous) New York edition of his novels, in which he wrecked the ending of The Aspern Papers and translated some of the...