In Noel B. Gerson's _Lillie Langtry, A Biography_ (Robt. Hale & Co.,
1971), p. 165 -- Gerson quotes a long passage that Twain wrote
about Lillie Langtry:

"Contrary to what one would expect of a woman whose fame was
based on her beauty, Mrs. Langtry is an exceptionally intelligent
person.  She must read constantly because she is able to discuss
in detail any book, classical or modern, English or American or
French, that is mentioned to her.  I know she isn't shamming,
because I questioned her in some detail, and she KNEW the books.
She also reads the newspapers, and doesn't bother with the trivia.
She can talk about worldly affairs or financial matters or
whatever with the good sense one would expect of a man who
keeps up to date.  She meets a stranger as an equal, and
although she's so pretty her beauty is blinding, and she doesn't
rely on feminine charm.  She's what she is, and she expects one
to take her or leave  her.  She is good company with her friends,
but it would be hell to be married to her.  She's too damn
bright."

Unfortunately, Gerson does not provide the source of this Twain
quote.  Is this a passage from a previously unpublished letter,
essay, or newspaper interview??  Any ideas when or where Twain might
have met Lillie Langtry?  There is no reference to Langtry in
Twain's autobiography, or Paine's biography, or any volume
of _Notebooks and Journals_.

Thanks for any info,
Barb