Borax
Borax ({not transcribed}) , noun
[Old English boras, from French borax, earlier spelt borras; compare Late Latin borax, Sp. borraj; all from Arabic bawraq, from Persian bōrah.]
A white or gray crystalline salt, with a slight alkaline taste, used as a flux, in soldering metals, making enamels, fixing colors on porcelain, and as a soap. It occurs native in certain mineral springs, and is made from the boric acid of hot springs in Tuscany. It was originally obtained from a lake in Thibet, and was sent to Europe under the name of tincal. Borax is a pyroborate or tetraborate of sodium, Na2B4O7.10H2O.