BLEACHING OF OTHER VEGETABLE FIBRES China grass is bleached like cotton, and hemp like linen, but the latter fibre is seldom bleached. In the case of jute severe treatment with alkali is avoided, and the goods are subjected to chemicking with sodium hypochlorite and souring only. Straw is bleached by steeping in fairly strong hydrogen peroxide for periods varying from i 2 hours to several days, followed by exposure to the action of sulphurous acid. Artificial silk pre pared by the viscose process is obtainable in a condition which is known as "unbleached"—this product has a cream colour resembling that of grey cotton and an opalescent lustre. This characteristic appearance is due to the presence of sulphur, for when this is removed the whiteness and silky lustre appear immediately.