A viral Instagram clip shows a British aristocrat on a yacht upset about running out of tonic water. This scene reveals a surprising truth: gin and tonic was once essential medicine, not just a refreshing drink. The character, Sir Percy de Courcy, played by Terry-Thomas in the movie Spanish Fly, explains, "The Empire was built on gin and tonic. Gin to fight the boredom of exile, and quinine to fight malaria." Malaria was a deadly threat to the British Empire in hot, mosquito-filled colonies like India and Africa. Disease killed more people than war. Quinine, extracted from the bark of the cinchona tree, was the only effective way to prevent malaria. But quinine was very bitter and hard to drink. To make it easier to take, quinine was mixed with water, sugar, and bubbles creating tonic water. Adding gin, cheap and given to soldiers, masked the bitterness. Lime or lemon was added to prevent scurvy, a vitamin C deficiency disease. This mix became a daily health ritual. It kept British soldiers and officials safe from malaria and scurvy. It also helped them endure the boredom and hardships of colonial life. Winston Churchill noted that gin and tonic "had saved more English lives, and minds, than all the doctors in the Empire." While it didn't help Britain conquer colonies, it helped keep them alive in malarial regions. So, gin and tonic was a crucial part of the British Empire’s survival story, blending medicine and morale in a glass.