From The Food Encyclopedia by Jacques Rolland and Carol Sherman
Also quinine water, tonic. A carbonated beverage containing lemon and lime juices and quinine that is usually used as a mixer in cocktails. The most famous of these is gin and tonic, routinely drunk by late-19th-century British colonists in West Africa, a part of the world then called the "white man's grave." The quinine, commonly prescribed as both a preventative and a treatment for malaria, made this drink both thirst quenching and therapeutic.
