You are the tonic to my gin ;) But what exactly is tonic? Like gin, it has its origins as medicine. The legend starts in the 17th century in Peru, where a Spanish countess has a severe fever due to malaria. A local medicine man gives her a drink made from the bark of the native quinquina tree, and she heals!

She takes it with her to Europe where everyone is wildly enthusiastic about the quinine and it soon becomes more expensive than gold.
During the English occupation of India, the soldiers are given quinine against malaria, but they add a spoonful of sugar to mask the bitter taste. The officers mix the stuff with their beloved gin and some sparkling water: the gin & tonic is born!