“Originally, tonic water was disgusting,” he says. “In the army, they just mixed bark dust [from the cinchona tree, the source of quinine] with water. It’s horribly bitter, doesn’t dissolve well, and gets stuck in your throat, leading to fits of hacking.” Gin turned out to be key in getting the medicine down, he explains. “Tonic wasn’t very soluble in water. Gin made it so, and the oils from the spirits and botanicals actually fuse with tonic to make it more palatable.