The production of essential oils was industrialized in the first half of the nineteenth century, owing to an increased demand for these matrices as perfume and flavor ingredients (Rowe, 2005). As a consequence, the need to perform their systematic investigation also became unprecedented. It is interesting to point out that in the second edition of Parry's monograph, published in 1908, about 90 essential oils were listed, and very little was known about their composition (Parry, 1908). Further important contributions to the essential oil research field were made by Semmler (Semmler, 1907), Gildemeister and Hoffmann (Gildemeister and Hoffman, 1950), Finnemore (Finnemore, 1926), and Guenther (Guenther, 1972). Obviously, it is unfeasible to cite all the researchers involved in the progress of essential oil analysis.