英语词源字典 - 在线词源网站

bleach (v.)[bleach 词源字典]: Old English blæcan "bleach, whiten," from Proto-Germanic *blaikjan "to make white" (cognates: Old Saxon blek, Old Norse bleikr, Dutch bleek, Old High German bleih, German bleich "pale;" Old Norse bleikja, Dutch bleken, German bleichen "to bleach"), from PIE root *bhel- (1) "to shine, flash, burn" (cognates: Sanskrit bhrajate "shines;" Greek phlegein "to burn;" Latin flamma "flame," fulmen "lightning," fulgere "to shine, flash," flagrare "to burn;" Old Church Slavonic belu "white;" Lithuanian balnas "pale").

The same root probably produced black; perhaps because both black and white are colorless, or because both are associated with burning. Compare Old English scimian, related to the source of shine (n.), meaning both "to shine" and "to dim, grow dusky, grow dark." Related: Bleached; bleaching.[bleach etymology, bleach origin, 英语词源]
bleach (n.): "act of bleaching," 1887; "a bleaching agent," 1898, probably directly from bleach (v.). The Old English noun blæce meant "leprosy;" Late Old English also had blæco "paleness," and Middle English had blech "whitening or bleaching agent."
leach (v.): Old English leccan "to moisten, water, wet, irrigate," (see leak (v.)). The word disappears, then re-emerges late 18c. in a technological sense in reference to percolating liquids. Related: Leached; leaching.
magnesia (n.): late 14c., in alchemy, "main ingredient of the philosopher's stone," from Medieval Latin magnesia, from Greek (he) Magnesia (lithos) "the lodestone," literally "(the) Magnesian (stone)," from Magnesia, region in Thessaly, which is said to be named for the native people name Magnetes, which is of unknown origin. The ancient word, in this sense, has evolved into magnet. But in ancient times the same word, magnes, was used of lodestone as well as of a mineral commonly used in bleaching glass (modern pyrolusite, or manganese dioxide).

In Middle Ages there was some attempt to distinguish lodestone as magnes (masc.) and pyrolusite as magnesia (fem.). Meanwhile, in 18c., a white powder (magnesium carbonate) used as a cosmetic and toothpaste was sold in Rome as magnesia alba ("white magnesia"). It was from this, in 1808, that Davy isolated magnesium. He wanted to call it magnium, to stay as far as possible from the confused word magnesia, but the name was adopted in the form magnesium. Meanwhile from 16c. the other name of pyrolusite had been corrupted to manganese, and when, in 1774, a new element was isolated from it, it came to be called manganese.

Magnesia in its main modern sense of "magnesium oxide" (1755) is perhaps an independent formation from Latin magnes carneus "flesh-magnet" (c. 1550), so called because it adheres strongly to the lips.
purgery (n.): "bleaching room for sugar," 1847, from French purgerie (1838), from purger (see purge (v.)). For the legal term, see perjury.
hypochlorous acid: "A weak acid with oxidizing properties formed when chlorine dissolves in cold water and used in bleaching and water treatment", Mid 19th century: hypochlorous from hypo- (denoting an element in a low valency) + chlorine + -ous.