Shellac
lac purified by melting and straining through coarse cotton bags. It occurs in commerce in thin, translucent, hard hard flakes, varying in color from yelbrown to black, sp. gr. 1.139, and is soluble in alcohol, hydrochloric acid, acetic acid, potash, soda, borax, and ammonia. A bleached or white variety is prepared by dissolving crude lac in potash or soda , filtering and passing chlorine gas into the filtrate till all is precipitated; this is then collected , washed with water, slightly heated, and then twisted into sticks. Shellac is chiefly used in var- , and in the manufacture of sealing wax.