Emily Dickinson Lexicon

BLEACH, v.t. [Sax. blæcan; D. bleeken; G. bleichen; Sw. bleka; Dan. bleeger, to whiten or bleach; D. blyken, to appear, to show; Dan. blik, a white plate of iron, or tin plate; bleeg, pale, wan, Eng. bleak; Sw. blek, id.; bleka, to shine; Ar. بَلَقَ balaka, to open or be opened, to shine; بَلَجَ balaja, id. It is not improbable that blank and blanch are the same word, with a nasal sound casually uttered and afterward written before the final consonant.]

To whiten; to make white or whiter; to take out color; applied to many things, but particularly to cloth and thread. Bleaching is variously performed, but in general by steeping the cloth in lye, or a solution of pot or pearl ashes, and then exposing it to the solar rays. Bleaching is now generally performed, on the large scale, by means of chlorine or the oxymuriatic acid, which has the property of whitening vegetable substances. – Cyc.