Further Studies on the Conducting Properties of Human Skin to Direct and Alterticzting Current.

Summary. The resistance of 4.9 cm2 of the stratum corneum to direct current (2 volts), when inorganic salt solution is used as contact electrolyte, is found to be lower at cathodic conduction1 where inorganic anions pass into the stratum corneum than at anodic conduction1 where inorganic cations pass into the corneous layer. A rise in the concentration of the contact electrolyte, or in the valency of the cations — both changes producing an increase in the concentration of the inorganic anions of the contact electrolyte –leads to a further reduction of the resistance at cathodic conduction, while the resistance at anodic conduction is not changed. Measurements of the potential across the stratum corneuni before, during and after conduction of direct current, with anodic and cathodic direction, indicate that the greater resistance to anodic conduction is not due to electrolytic polarization. Determination of the a. c.‐resistance at 200 and 2 000 cycles after anodic and cathodic d. c.‐conduction shows that the difference in resistance to the two directions of current is due to a different conductivity of the stratum corneum. The different conductivity is caused by the fact that the stratum corneum is morp permeable to inorganic anions than to inorganic cations. It is assumed that the reason is that the stratum corneum, like other organic membranes, is positively charged.