Mastic

Mastic, a species of gum-resin yielded by the Mastic or Lentisk tree (Pistacia lentiscus, natural order Terebinthaceae). It oozes from cuts made in the bark, and hardens on the stem in small round tear-like lumps of a light straw colour, or, if not collected in time, it falls on the ground; in the latter state it acquires some impurities, and is consequently less valuable. The chief use of this gum-resin is in making the almost colourless varnish for varnishing prints, maps, drawings, &c. It is also used by dentists for stopping hollow teeth, and was formerly employed in medicine. It is imported in small quantities, chiefly from the Morocco coast, but some is brought from the south of Europe and the Ægean.—The name of mastic is also given to oleaginous cements, composed of about 7 parts of litharge and 93 of burned clay, reduced to fine powder, made into a paste with linseed-oil.