It was not until World War II that the studies of the French chemist Ren?e Maurice Gattefosse were continued through the work of Jean Valnet. Jean Valnet had used essential oils and other distilled plant material as a method of treating gangrene in wounded soldiers. While it was not necessarily a cure, there were many cases when Jean Valnet was capable of saving soldiers lives using these essential oils ? a very helpful discovery during wartime crises.