In the 19th century, British officers stationed in India faced the threat of malaria. To combat this, they consumed quinine, known for its anti-malarial properties, but its bitter taste was off-putting. To make it more palatable, they mixed quinine with soda water, sugar, lime, and gin.
This concoction not only masked the bitterness but also became a refreshing and popular beverage—the gin and tonic we know and love today.