The original experiments, I think, of this sort were not done with
resistive paper but with flat tanks of conducting solutions in which metal
objects were placed. I wonder if any of the issues you have been
discussing could be probed by looking at the patterns as a function of the
conductivity of the liquid. If the conductivity is high, is seems to me
that the patterns would be dominated by conduction effects, as they are on
paper. Whereas is the conductivity was very low, you might expect to see
something that looks more electrostatic...or so it would seem.
what do you'all think?
joe
Joseph J. Bellina, Jr. 219-284-4662
Associate Professor of Physics
Saint Mary's College
Notre Dame, IN 46556