アルカリ

Arabic al-qaly is the older source behind Japanese アルカリ. The Arabic al- is the definite article, and qaly referred to ashes of saltwort and related plants used to make alkaline substances. Medieval Latin chemistry adopted alkali, and European languages including Dutch used forms such as alkali before modern chemistry entered Japan through books and schools. The Japanese route runs through Rangaku and Meiji science. Dutch chemical books were read in late Edo Japan, and Udagawa Yōan's 1837 Seimi Kaiso is a key work in the formation of Japanese chemistry vocabulary. After 1868, school chemistry placed アルカリ beside 酸, 塩基, and 中和. The meaning moved from plant ash material to a chemical class used in laboratory classification. In present Japanese, アルカリ refers to alkaline substances or alkaline character. Common compounds include アルカリ性, アルカリ乾電池, and アルカリ金属, a group that includes lithium, sodium, and potassium. English alkali is mainly a noun, while Japanese アルカリ often works as the first part of compounds. A concrete classroom fact is pH 7: values above it are called アルカリ性 in school science, while values below it are 酸性.