鳥取県三朝温泉に於ける二，三の放射性元素の存在について

The author tried to measure RaB, RaC and ThB in the hot spring waters using G-M counter and proved the existence of RaB and ThB in Misasa Hot Springs. To 100 liters of spring water ahout 20 gms of ferric chloride and then sodium hydroxide were added. Precipitate was dissolved in hydrochloric acid and after adding bismuth and lead, the solution was saturated with hydrogen sulfide. The precipitate of sulfides was filtered and ignited to ashes after drying. The β-activity of the ashes was measured by a mica-window type G-M counter with the recording circuits of scale of 16. Natural background was 50±5 connts per minutes. Six spring waters of Misasa, namely "Spring of Branch Laboratory", "Nakayu", "Gunze" "O-T-R", "Jwayu", and "Tsukiminoyu" were investigated. RaB was detected in all samples. ThB was found only in "Gunze" and "O-T-R". ThB content of "Gunze" was estimated, to be roughly 1×10(-12) Curie units per liter.