Mark Sheridan, age 13, of Bessemer, Ala., for his question:

HOW IS TURPENTINE MADE?

Turpentine is a resinous sap obtained from pine trees. The liquid we buy as turpentine is oil of turpentine, or spirits of turpentine. This is obtained by distilling the real turpentine.

Turpentine in the United States for the most part comes from the longleaf yellow pine and the slash pine, which grow throughout the Southern states. Thick, gummy sap is collected in metal cups. It is then boiled with part turning into a vapor. The vapor is passed through a coil of pipe cooled by water. It condenses into oil of turpentine.

Oil of turpentine is used as a thinner in paints and varnishes. It is also used to dissolve rubber and other gums in the manufacture of celluloid and various plastics.