Biological applications of large electric fields: Some history and fundamentals

The history of electric fields in biology is summarized briefly. Physical c oncepts important for explaining the action of electric field pulses on bio logical objects are reviewed: relation of pulse width to frequency spectrum ; precise meaning of "conductor'' and "dielectric"; electrical properties o f living tissues; translatory and rotational motion of electric charges and dipoles; effects of inhomogeneity, diffusion and viscosity; conditions for validity of linear models; electrical mobility of ions in membrane channel s and membranes; conditions for radiation; reflection, refraction, and pene tration of radiated fields; effect of radiated magnetic fields on chemical reaction rates; radiation pressure; electrostriction; the problem of distin guishing between thermal and nonthermal effects. The rationale for close co llaboration among biologists, engineers, physicists, and physicians is disc ussed.