The author studied ultrastructural changes of the skin induced by exposure to the water. Rats were exposed on the distilled water and physiologic saline of their legs for 8, 16, 24, 36 and 48 hours respectively. Exposed skins were examined by light and electron microscopes. The results obtained were summarized as follow：
Light microscopically, exposed skin showed edema and mild inflammatory infiltration on the
dermis and subcorneal abscess formation from 8 hours, which were more prominent after 16 hours and increasing in intensity till 24 hours, but remained in same degree after that time.