From a very early age onwards, people's attention had been attracted to the volatile substances, characterized by strong smells or flavours, which are among the large variety of substances which form within plants; these were used partly for therapeutic purposes, but in particular for increasing pleasurable sensations by nerve stimulation.
In bitter almond oil, like in a great number of other substances that previously had been counted among the 'aromatic compounds' on behalf of their strong smell, a derivative of benzene is present. The special properties of benzene and its derivatives are caused by the typical arrangement of their carbon atoms.
It has been possible to trace historically back to a very early age the taxes which were imposed on medicines, spices and similar substances in German towns. Thus, for instance, one finds that in the year 1500, thirteen, in 1540, thirty-eight, and in 1708, already one hundred and twenty vegetable oils are mentioned.