Aroma
In chemistry, ancients called aroma the spirit or the fragrant effect coming from plants. Vegetables give off the aroma that is a thin and a volatile compound spreading through the air and reaching men and animals olfaction. There are many kinds of aroma depending on the numbers of plants, so every aroma changes in every plant, according to the circumstances.
Font: L.S. Lenormand, L'Art du distillateur, Parigi 1817.