http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf
I. BREVIK, EXPERIMENTS IN PHENOMENOLOGICAL ELECTRODYNAMICS AND THE ELECTROMAGNETIC ENERGY-MOMENTUM TENSOR, pp. 143-144: "We shall first give some supplementary comments on the well known situation shown in fig. 1, where two parallel condenser plates are partially immersed in a dielectric liquid. When a horizontal electric field E is applied between the plates, the liquid will rise within the condenser to some equilibrium height h. [...] What makes the liquid rise between the plates? Certainly not the electrostriction force."

But the rising dielectric liquid can do useful work, e.g. by lifting some floating weight, and the crucial question is: At the expense of what energy is the work done? Since, by switching the field on and off, we do no work on the system, the energy supplier can only be the ambient heat. That is, the system can cyclically lift floating weights at the expense of heat absorbed from the surroundings, in violation of the second law of thermodynamics.

More illustrations:

https://www.youtube.com/watch?v=aHNwvfXUYb4
Rise in Liquid Level Between Plates of a Capacitor

http://www.youtube.com/watch?v=T6KAH1JpdPg
Liquid Dielectric Capacitor

https://www.youtube.com/watch?v=ACDxurDAmyg
Chapter 11.6.2: Force on a liquid dielectric

Pentcho Valev