So say for example you have some silver snowflakes growing on the bottom of
your finished jar of EIS.  What actually entices silver ions in that
solution to give up an electron and become metallic, stuck to the rest of
the snowflake.

How might this apply in vivo also.  I recall Marshall's write up suggested
that particles provide sites of "nucleation"  (which I guess just means
places for plateout to start?), and silver chloride plateouts out on them.
 And it does not matter that the particles are not metallic silver as in
the case of the snowflake?

David