The leaves of Cupressus Lambert/ana, Carr. (C. macrocarpa, Hartw.), a tree often met with in the gardens of the Riviera, yield upon distillation about 0,1 p.c. of oil; d1600,8656; aD + 31°53'; A. V. 1,5; E. V. 13,9; E. V. after acetylation 50,82; forms a turbid solution with 9 to 10 vol. of 80 p.c. alcohol, a clear solution with 0,5 vol. and more of 90 p. c. alcohol. The greenish-yellow oil has a balm-like odor, due probably to the presence of citronellal. When shaken with acid sodium sulphite solution, the presence of aldehyde-like constituents could be demonstrated, but their amount was too small for identification. The non-aldehydic constituents have a peppermint like odor and may contain cymene1).