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HYDRO‐ELECTRIC STATION. Corrosion at Kamsk—I. The first of a series of articles on research at the Permsk State University, chiefly in connection with pitting corrosion. During the past 10 years several large hydro‐electric power stations have been built in the Soviet Union, and the severe corrosion to which much of the ironwork is exposed has become a serious problem. The station on the Kama River (central part) has been the subject of special studies, including samples of the river water that is much contaminated from various causes. Sulphate and chloride ion concentration is particularly high as compared with other Russian rivers, as shown in two tables, the second of which gives details for the several dams and spillways, up to No. 23 on the left bank. Some particulars are also given of the steel used. Special attention was given to micro‐biological studies; also of various protective coatings used, e.g. bituminous lacquers; also zinc sheeting and others. Pitting corrosion was severe in places through electrochemical action. It was found that, in the Kama water, there is a high content of iron bacteria, such as Leptothrix (two forms) and Crenothrix, with others. These favour electrochemical corrosion, but also take part in the formation of concretions that cover part of the metal surface and prevent ingress of oxygen. In such parts, forming anodes of local cells, corrosion develops rather deeply in the metal. The pH value of the water below the concretions is lowered. The bituminous lacquers were found to be of poor quality for the purpose of protection.—(V. V. Kuznetsov et al., Zh.prikl. Khim., 1961, (1), 187–193.)