Yoshinao Kozai

Agricultural chemist. Born in Kyoto in December 1820 (Genji 1). His father, Senzo, died when he was 12 years old. In 1881 (Meiji 14), he entered Komaba Agricultural College and studied under Oscar Kellner (1851-1911). He graduated from the school's agricultural chemistry department in 1886, when the school merged with the Tokyo Forestry School and was renamed Tokyo Agricultural and Forestry School, where he became an assistant professor and then a professor. In 1890, the school became the College of Agriculture of Tokyo Imperial University, where he became an associate professor. In 1892, he married the female writer Shimizu Shikin. In 1895, he went to Germany to study agricultural chemistry, and in 1900 (Meiji 33), he returned to Japan and became a professor at the College of Agriculture of Tokyo Imperial University. In 1905, he served as an engineer and director of the Agricultural Experiment Station, in 1911 he became president of the College of Agriculture of the Imperial University of Tokyo, and from 1920 to 1928 (Taisho 9 to Showa 3) he served as president of the Imperial University of Tokyo.

In agricultural chemistry, he conducted pioneering research into subjects that had not yet been explored at the time, such as the biochemistry of tea, the effectiveness of various fertilizers in rice and field cultivation, soil depletion and fertility, and pointed out the need for phosphate fertilizers and the necessity of pure yeast culture in sake brewing.He also worked hard to rebuild Tokyo Imperial University after the Great Kanto Earthquake of 1923.At the time of the Ashio Copper Mine Poisoning Incident, he analyzed the soil in the Watarase River basin at the request of farmers, confirmed the presence of copper from the mine, and cooperated with the farmers' demands for compensation, working hard to provide relief.

[Taoist Master]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

農芸化学者。元治(げんじ)元年12月京都に生まれる。12歳のとき、父仙蔵と死別。1881年（明治14）駒場(こまば)農学校に入学、ケルネルOscar Kellner（1851―1911）に学ぶ。1886年同校農芸化学科を卒業、この年同校が東京山林学校と合併し東京農林学校と改称され、その助教授、ついで教授となる。1890年、同校がさらに東京帝国大学農科大学となるに及び同大学助教授となった。1892年、女流作家清水紫琴と結婚。1895年ドイツに留学し農芸化学を研究、1900年（明治33）に帰国し東京帝国大学農科大学教授となる。1905年、農事試験場技師および場長を兼任、1911年東京帝国大学農科大学学長、1920～1928年（大正9～昭和3）東京帝国大学総長を務めた。

　農芸化学上の研究としては、茶の生化学、各種肥料の稲作および畑作における肥効、土壌の消耗や地力の研究、またリン酸肥料の必要性や日本酒醸造における酵母の純培養の必要性を指摘するなど、当時未開発であった課題について草分け的研究を行った。また1923年の関東大震災後、東京帝国大学の復興に尽力した。足尾(あしお)鉱毒事件に際しては、農民の依頼に応じて渡良瀬(わたらせ)川流域の土壌を分析し、鉱毒の銅の存在を確認するとともに、農民の補償要求に協力し、その救済に尽力した。

［道家達將］

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