An earlier version of one developed by “Dr. James A. Cambell, Professor of Ophthalmology and Otology at the Homeopathic Medical College Missouri and Oculist and Aurist to the St. Louis Children's Hospital.  His “New EarElectrode” consists of two curved movable arms passing through a brass joint with thumb set-screw. The upper end of each insulated arm terminates in a spherical metal electrode for positioning in the ears and over the eyes. Only the weakest current should be used and for not more than 5 minutes.  The local effect can be diminished by covering the electrodes with thin chamois skin, or even moistened cotton flannel.”