This revised & expanded handbook is an in-depth guide to essential oils, providing a research-based overview of the field of aromatherapy. It looks at the essential oils used in contemporary aromatherapy practice, with an emphasis on the underlying philosophical approaches & therapeutic applications. The book begins with an explanation of the theoretical history of aromatherapy in Greek, Chinese & Ayurvedic medicine. It then gives a detailed account of how essential oils are created, how & where aromatherapy is used, the underlying pharmacology, & the current research. The characteristics of over 100 essential oils, absolutes & resinoids are explored, including botanical & chemical information, usage & combinations. This will be an indispensable text for all students & practitioners of aromatherapy & related disciplines, as well as anyone interested in the use of essential oils for health & well-being.