Abstract
Electric charges generated by breaking of a piece of single crystal ice, polycrystalline ice including numerous bubbles, and polycrystalline ice including few bubbles were measured by the use of electrometers. The charge generated was only 5×10-3 e. s. u, cm-2 in single crystal ice, while in polycrystalline ice 1 e. s. u. cm-2 charge was obtained. It was found that in case the polycrystalline ice including numerous bubbles under temperature gradient was broken in two pieces, the warmer part was charged negatively and the colder part positively.
