a) Colorimetoric determnation of the minute amount of antimony and antimony contend of Yanahara Hot Spring. To 5cc of sample soln., not containing the second family other than antimony. add 0.2 cc of 10% polyvinyl alcohol aqueous solution. Adjast HCI eoncentration to approximately I. N. Add I cc of hydrogene sulfide solution and sbake. Then measure the reruting yellow or orange color by photometer. Antimony content of Yanahara Hot Spring was 0.1±0.03 g per liter by the above mentioned method. b) Quantitative determination of the free mineral acid. Precipitate iron and aluminium as complex fluorine salts and change the sulfate ion into alkali sulfate, so that it can not liberate free acid. Then titrate with alkali using phenol red as an indicator. c) Iron and coprer in thermal waters and minerals of Yanahara Hot Spring. Ferous ion content of Yanahara Hot Spring (60℃) was 14.6g per liter and its copper content was 0.44g per liter. both being the highest record in Japan. A green and a bluish green minerals ware found, crystalyzed near the Hot Sprig. The latter was apisanite (Cu(0.25) Fe(0.75) S0(4・8.8) H(2)O) and the former proved to be a pure melanterite (Fe S0(4).7H(2)O). d) A modified method to detect sulfides of the second family. Using zinc-amalgam the author succeeded to avoid the liberation of sulphur and to detect the yellowish or orange colored sulfides, such as ausenic, antimony or tin sulfide. e) Paper chromatography applied to the analysis of heavy metals in vitriol waters. 4 kinds of vitiol waters were investigated. Paper chromatography proved to be excellent in detecting the metals of the second family, such as tin, antimony, and ansenic
