John Coakley Lettsom

In the 18th century, as tea was becoming a necessity in British life, an Englishman named John Coakley Lettsom wrote a book titled "The Natural History of the Tea-tree: With Observations on the Medical Qualities of Tea, and Effects of Tea-drinking." The book discusses in detail the botanical characteristics of tea, tea manufacturing, types of black and green tea, and the effects on the human body, based on literature and experimental results.