In 1910, the Nobel Prize in Chemistry was awarded to Otto Wallach in recognition of his services to organic chemistry and the chemical industry by his pioneering work in the field of alicyclic compounds. The long and the short of Wallach's work is that it centered around the essential oils whose core structure could not be traced back to benzene or one of its derivatives. A breakthrough came with the identification that most of these compounds have ten carbon atoms. Wallach also worked on a limonene series of compounds, obtaining a whole series of racemic mixtures from their optically active constituents by starting with either the laevo or dextro-limonene. Wallach's contribution to the elucidation of the structures of the terpenes helped to conclude the triumph of structural theory, something that is integral to synthesis since it allowed insight into the chemical structure of the products. Wallach himself recognized the importance of his work to the fragrance industry.