三朝温泉の化学的研究（第16報）温泉沈澱物について

A calcareous sinter, siliceous sinter, flowers of sulfur, mangan wad, and ferric oxide were found as thermal deposits in Misasa. And the most strongly radioactive sinter deposit in Japan, mangan as its chief constituent, occured in Misasa. A mechanism of its biological production was investigated, but proved negligible. The color of deposits was described with the degree of hue, luminosity and saturation. No simple relationship was recognized between the color, content of iron or mangan, and radioactivity. The soluble silica in thermal waters does not coprecipitate with iron and aluminum at room temperature, but it coprecipitates with aluminum at high temperature. Magnesium ion in spring waters is effective on the coprecipitation of aluminum. A colloidal silica does not exist in the thermal waters of Misasa, but in the thermal sinter deposit an alkalin soluble colloidal silica was contained less than 0.1 per cent. Coexisting bicarbonate ion is proved to be effective on the production of calcareous sinter. Fluorine and arsenic were found concentrated in the sinter deposit.