It's doubtful that Freud and Twain actually met while Freud was in Vienna,
although, as noted previously, and cited in the Dolmetsch book, Freud
attended a Twain lecture and, much later, made a reference to Twain in The
Psychopathology of Everyday Life.  At the time the Clemens family lived in
Vienna, Freud was still a practicing neurologist, although he had been
involved with Josef Breuer in the case of Anna O. and was currently
exchanging ideas about the role of the nose in psychopathology with the
crackpot Wilhelm Fliess.  This was two years prior to the publication of The
Interpretation of Dreams, which didn't sell well even in Europe.  Freud
didn't get much attention in the U.S. until he visited Clark University in
Worcester, Mass., at the invitation of G. Stanley Hall (a real scientist) in
1909 and it wasn't until after the First World War that Freud's work
attracted significant attention in the U.S.  At the time Twain lived in
Vienna Freud's ideas were not generally accepted
even in the Vienna Medical establishment and his best-known publication was
likely an article he wrote concerning the nervous system of a form of
planaria (a snail-like creature), a piece of writing which, from a
scientific standpoint, still holds up well.

Martin Zehr
Kansas City, Missouri