海水, かん水中に存在するNa⁺以外の共存イオンが膜抵抗におよぼす影響を2種類のイオン交換膜について調べた.
1.陽イオン膜の場合にはMg²⁺, Ca²⁺は膜抵抗を増大させ, K⁺は低下させる.海水中での膜抵抗は0.5N NaCl中の約2倍となつた. 液濃度が増大するとDonnan吸着イオン量が大となり膜抵抗は低下する.
2.陰イオン膜の場合にはSO^2-₄は膜抵抗を増大させる傾向があるが, その影響は小さい.
3. 海水, かん水のような多成分系溶液に陽イオン膜を平衡させた場合の膜抵抗は, 全膜面積に対する面積比が膜中における各イオンの吸着率に等しい膜面積をもつ各イオン型膜の並列抵抗に近似する.
4. 陽イオン膜の海水, かん水中におけるCa²⁺, Mg²⁺吸着率はNa⁺よりかなり大であつた.
5.Donnan吸着イオン量は溶液濃度が1N以上になると膜の収縮などの影響で理論値とくらべて小さい値を示す.

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Lithium contained in sea water was determined by atomic-absorption spectrophotometry by using air-hydrogen flame. Sodium, potassium and chloride ions so significantly interfered the absorption of lithium that the precise result could not be obtained even when the calibration curve was constructed by addition of lithium standards. Lithium was separated from other alkali metals by extracting the chloride salt with iso-amyl alcohol, and the resulting organic solution was sprayed into the flame. The sensitivity of this procedure was comparatively low, but the reproducibility was much better than in case aqueous solution was used. Thus, more accurate results were obtained. Some sea-water samples were analized, and their lithium content was found to be about 140μg/1 in coastal and 170μg/1 in open sea water.

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The authors have made a study on the behaviors of minor components in the process of concentrating sea water. The present study dealt with the behaviors of zinc and cobalt ions by using radioactive tracer ⁶⁵Zn and ⁶⁰Co.
Zinc and cobalt ions behaved in the similar manner, and indicated a greater loss from the solution evaporated at higher temperature. In contrast with strontium, calcium and phosphate, however, they were never rapidly lost in the final stage of concentration. Therefore, 30-50% of them remained in the solution even after 95% of sea water was evaporated. Most of the zinc and cobalt deposited were distributed into insoluble gypsum deposit, and almost none of them were contained in soluble salt.
Zinc and cobalt in sea water were determined spectrophotometrically with zincone and nitroso R salt, after they were concentrated and separated coprecipitation with aluminium hydroxide. Zinc was concentrated and separated by ion exchange procedure, and cobalt by solvent extraction with dithizone, respectively. As the result of analysis of several sea-water samples, zinc was estimatezd at 0.3-0.5μg/1, while cobalt at 4-10μg/1.

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前報でイソブタンを基にして, これに他のC₄級炭化水素の-つを混合した系について導いた平衡圧と混合率に関する一般式を, プロパンー正ブタンの混合系に適用し, 種々の温度における平衡圧を算出した, その絶対値は実測値といくらかの差はあるが, その傾向は十分に察知でき, プロパンが水和物を生成する限界の組成を予測するには有効であることを知つた.なお, プロパンーブテンー1の系についても同様であることを確認した.
以上の結果から, 海水を氷点以下かなりの低温まで本法で冷凍する場合, プロパンを基にして, これに単独では水和物を生成しえないC₄級炭化水素を混合した冷媒を用いることにより, プロパン水和物の生成を回避するとともに, 平衡圧を一層常圧近くまで下げて作業するのに適当な冷媒の組成を求める指針がえられた.

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