If we go through with this idea of
a
the
private experience which we don't know we can't talk of a certain private experience either, because
this expression is taken from the case in which what we don't know is something like say, whether if he says he sees red he sees red & not perhaps blue green or yellow.
  In which it alludes to a certain class of experiences which we know though we don't know which one of its members he has. Rather ◇◇◇ the private
impressions
experiences
ˇwhich we imagine as the background to the foreground of our actions dissolves into a mist which we wished to refer to talk about & imagined to be back of our action dissolve into a mist w    Rather the private experiences which we imagined as an unknown x a, y, z etc. behind our acti actions, loose their individualities & dissolve into a mist & into nothing.