Spruce and hemlock oils are produced in Canada and the northeast of the
United States by steam distillation of needles and twigs from Picea mariana
(Mill.) Britton, Sterns et Poggenb. (black spruce), Picea glauca (Moench)
Voss var. glauca (white spruce), Tsuga canadensis (L.) Carrière (Hemlock
spruce), and related species. They are very pale to light yellow liquids with a
pleasant odor reminiscent of pine needles.
d2525 0.900–0.915; n20D 1.4670–1.4720; α20D ?25 ° to ?10 °; solubility: 1 vol
in at least 1 vol of 90% ethanol; solutions may become hazy when >2 vol of
90% ethanol are added; ester content (calculated as bornyl acetate): 37–45%.
