The Chemistry of Essential Oils:

An Introduction for Aromatherapists,

Beauticians, Retailers and Students


By David G. Williams

Second Edition, 2008

189 x 246 mm, 7.5" x 10"

Hardback, 408 pages

ISBN: 978-1870228-31-2



Postage rate C

*Click here for UK and international postage charges











The first edition of this work, published in 1996, became an instant classic because it was the first textbook of its kind to bring to the reader an introduction to the subject from first principles. It was addressed primarily to practitioners and students of aromatherapy, who are, again, the main intended audience. However, it should also appeal to beauticians wishing to extend their knowledge into the fragrance area of cosmetic science, to retailers of essential oils and perfumes and to cosmetic scientists wanting to learn more about the chemistry involved. The first two chapters, Some Basic Chemistry and Hydrocarbons aim to pave the way to an understanding of the simple structures forming the backbones of the molecules of constituents of essential oils. In Chapter 3, Functional Groups Containing Oxygen, Nitrogen and Sulphur, the main chemical types of constituents of essential oils are discussed.

Chapter 4, Essential Oils and Carrier Oils, is concerned mainly with the geographical and botanical sources of essential oils, their preparation for the market, their properties, and their safety. The subject of Chapter 5 is explained by the title, The Odour Properties of Essential Oils, and gives many profiles of well-known essential oils, of essential oils, in terms of their "top" and "body" notes and "dryout".

The standard physicochemical and instrumental quality evaluation tests applied to essential oils are explained in Chapter 6, Quality Control of Essential Oils. Although every chapter has been revised, this chapter has been dramatically changed -- a total of 49 chromatograms of essential oils are provided, with many component ingredients identified. The chromatograms are mainly presented in pairs, so that the effect of using a different column can be seen. The chromatograms are preceded by an explanation of what is involved in gas-liquid chromatography and how the ingredients are measured.

Chapter 7, Isolated and Synthetic Fragrance Materials begins with a little history and goes on to a discussion of some of the latest research into the composition of the scents of living flowers. Chapter 8, Perfumery -- The Fragrant Art, is devoted to perfumery and includes suggestions for simple fragrance experiments with essential oils.

The subject of Chapter 9 is explained by it's title: Personal Fragrances. Many famous perfumes are listed, along with their date of introduction, their fragrance notes and their type. The final chapter, Burning the Midnight Oil is intended to help students to learn what they will need to know of the subject in order to approach their examinations with confidence.

A glossary lists over 450 technical terms associated with essential oils and an extensive index completes the book.

Some reviews of Chemistry of Essential Oils, 2nd edition

“This revised 398-page book is something I would highly recommend to any students of aromatherapy, or others, wanting to understand the chemistry and other issues surrounding the use of essential oils. ...This revised edition now includes many GLC charts on each different essential oil. These charts are very useful for people to see the differences between the same named oil from different geographical locations, and how that may or may not affect their olfactory and other properties.
The book taken as a whole, corrects a lot of the inaccurate information found in the popular aromatherapy type books, where the authors had a weak knowledge of essential oils trade. This author on the other hand, has a lifetime’s experience in the trades he writes about. ...The extensive section on “burning the midnight oil” is vital reading for anyone involved in studying. The glossary is extensive, turning the book into an excellent quick reference resource. It is for those people with a thirst for accurate knowledge about their trade.”
Matt Watt, December 2008, available at:


“The writing is unusually good for a reference book, and indeed could be held as a model of what serious nonfiction for the general reader can be. The graphic design and presentation of the tables and figures is exemplary....The heart of the book has long chapters on the odor properties and quality control of the oils....The book is so full of useful information, imparted in graceful prose, that it can be recommended unconditionally and with pleasure.”
Steve Hermann, President, Diffusion LLC, International Journal of Cosmetic Science, December 2009, Volume 31, Issue 6.