Science Past from the issue of July 1, 1961

WINTERGREEN VS. ALMOND IN ODOR PENETRATION TEST — Different chemicals produce different odors because vibrations within the molecules are different. This is the theory of Dr. R.H. Wright of the British Columbia Research Council  in Vancouver, Canada. He compared nitrobenzene, which has an almond smell, and methyl salicylate, which smells like wintergreen. Both these substances are much alike so far as vibrations are concerned, except that wintergreen has two additional frequencies that are missing in nitrobenzene.… In experiments with 12 volunteer sniffers, Dr. Wright showed that the wintergreen odor masked the almond smell about ten times more easily than almond masked wintergreen. The effect is not large … but it is distinct and in the direction predicted by the vibrational theory of odor.