Camper English’s new book Doctors and Distillers is the kind of summer read that cries out to be enjoyed with a spirit or cocktail in hand. An appropriate choice would be a small glass of Chartreuse. This potent elixir, inspired by a manuscript from 1605 and developed over centuries by Carthusian monks into a secret formula boasting a complex blend of 130 botanicals, is one of the most beguiling spirits in the world.

In the 19th century, Chartreuse was advertised as a treatment for everything from apoplexy to indigestion to the difficulties of childbirth. Today the full-strength “Elixir Vegetal” is still sold in French pharmacies, though it’s not yet exported to the United States due to the monks’ reluctance to divulge details of the recipe to federal regulators. Americans can purchase the namesake Chartreuse liqueur. Boldly herbaceous and 110 proof, it’s an intense experience when sipped neat. It’s more approachable in cocktails such as the Last Word, combined with gin, maraschino liqueur, and lime juice, a modern mixologists’ favorite, or in the 1970s concoction known as Swamp Water, a simple mix of Chartreuse, pineapple, and lime.