Best I can tell, this one entered circulation through a book of aphorisms
collected by investment guru, John Train, published in 1991. The book is
called Wit: The Best Things Ever Said, and the Twain quote was cited in
several reviews of the book upon its publication. Haven’t scene any
appearance of the quote prior to ‘91 and haven’t consulted Train’s book
yet. Maybe he provides a citation! But I wouldn’t bet on it. - MS

On Sun, Oct 27, 2019 at 3:10 PM Barbara Schmidt <[log in to unmask]>
wrote:

> Hal - a quick search of Mark Twain resources does not confirm this quote
> originated with Mark Twain. Newspapers from 1950 attribute it to playwright
> George S. Kaufman but not in direct reference to the work of Henry James. I
> think Alan Gribben would have included it in MARK TWAIN’S LIBRARY: A
> RECONSTRUCTION if it was authentic, but it is not in that edition.
>
> Barb
>
> On Sunday, October 27, 2019, Hal Bush <[log in to unmask]> wrote:
>
> > My friend Vivian Pollak, notes Dickinson scholar, sent me this query;
> > anyone know off the top??
> >
> >
> > Get Outlook for iOS<https://aka.ms/o0ukef>
> >
> >
> > Hi Hal,
> >
> > Here's one for you. Where and when did MT say in re Henry James, "Once
> > you've put one of his books down, you simply can't pick it up again." The
> > internet has different versions of the quote, but no source. And how's
> > everything--I'm teaching Daisy Miller tomorrow coming off Huck. The quote
> > is a transition----of sorts!
> >
> > Best,
> > Vivian
> >
>
-- 
Matt Seybold Assistant Professor of American Literature & Mark Twain
Studies Elmira College