THREAD, a small line made up of a number of fine fibres of any vegetable or animal substance, such as flax, cotton, or silk; from which it takes its name of linen, cotton, or silk thread.
Dyeing Thread Black. Linen and cotton thread may be dyed of a durable and deep black by solution of iron in four beer, in which the linen is to be steeped for some time, and afterwards boiled in madder. See the article DYEING, n° 87.
Thread may be easily bleached by the oxygenated muriatic acid discovered by Mr Scheele. This acid whitens cloth remarkably well, but it is still more advantageous for bleaching thread. M. Welter has formed at Lisse, with two partners, an establishment for bleaching thread with great success, and he has already begun some others. He has
(A) We add, on the authority of an experienced farmer, that of the six persons necessary to attend the thrashing machine, only two can in justice be charged to the account of the machine; namely, the person who manages the horses, and the one who feeds the machine: For in the usual mode of thrashing by the flail, it requires the same number of persons as the thrashing machine does to clear an equal quantity of corn from the chaff in the same time.
Threatening has found that 10 or 12 leys and as many immersions are required for some sorts of thread; and that the thread may be surrounded with the liquor, it is necessary to place it, quite loosely, in a basket, which permits the liquor to penetrate to all its surfaces: when the liquor is much weakened, it is still fit to be used for the bleaching of cotton.
Those who with more information upon the powerful effects of the oxygenated muriatic acid in bleaching, as well as on the cheapest method of preparing it, may consult a Paper written by M. Berthollet, and published in the Annales de Chimie, a translation of which is given in the Report. of Arts, vol. i.