A gas chromatograph, equipped with a flame ionization detector, was used to qualitatively and quantitatively analyze the monoterpenes of Virginia pine. The instrument was adjusted for optimum performance prior to sample analysis. Two packed columns with stationary phases of different polarity, Carbowax 20M and polyphenyl ether + Igepal + Versamid-9JO, were used predominantly for analytical determinations. However, a S.C.O.T. column coated with UCON LB550X stationary phase, was used for measuring some compounds. The monoterpenes of Virginia pines were analyzed from foliage, phloem, and bark distillates, pentane extracts of xylem resin and beetle pitch tubes, and foliage and tree-bole vapors. Qualitative determinations were made by comparing relative retention time with known chemicals and mixtures of chemicals, and by introducing these standards into the sample. Quantitative determinations were based on normalization of peak areas for the known components. Peak areas measured with a disc integrator for liquid samples, and with a planimeter for vapor samples. / Ph. D.