That an oil could be extracted from anise and fennel had been known since the Renaissance by the German alchemist Hieronymus Brunschwig (ca. 1450 – ca. 1512), the German botanist Adam Lonicer (1528–1586), and the German physician Valerius Cordus (1515–1544), among others.  Anethole was first investigated chemically by the Swiss chemist Nicolas-Théodore de Saussure in 1820.  In 1832 the French chemist Jean Baptiste Dumas determined that the crystallizable components of anise oil and fennel oil were identical, and he determined anethole's empirical formula.  In 1845, the French chemist Charles Gerhardt coined the term anethol — from the Latin anethum (anise) + oleum (oil) — for the fundamental compound from which a family of related compounds was derived.  Although the German chemist Emil Erlenmeyer proposed the correct molecular structure for anethole in 1866,  it wasn't until 1872 that the structure was accepted as correct. 
Hi, my daughter (12 yrs old)) suffers terribly from seasonal allergies. I had a friend (who sells oils from a well know company) recommend a capsule of lemon/lavender/peppermint essential oil blend to be taken orally daily. I started giving them to her for a few days and they have been helping. However, that is when I started to wonder and research about the safety of her taking them internally. I stopped giving them to her until I find out more info, but am still having her use the oils on the bottom of her feet – which don’t seem to be helping at all. I found this article and was intrigued, but is there anything different i should be considering because she is a child and not an adult. I want to help her, not hurt her in the long run. Thank you!