Answer: Gin and Tonic

The first known treatment (and preventative) for malaria was quinine—a bitter substance derived from the bark of the cinchona tree. When troops of the British East India Company stationed in India balked at drinking a bitter dose of water laced with quinine, the officers created a cocktail to help the medicine go down.

This cocktail, a mixture of water, sugar, lime, and gin, was a natural fit for the job as the troops were already given a ration of gin. Mixing it together to help the medicine go down easy as a delicious cocktail was a brilliant move—and one the vintage Gordon’s gin ad seen here pays tribute to.

The resulting mixture became the beloved modern cocktail, gin and tonic. If you’re trying to fight off malaria with a trip to the bar, however, we’d suggest a stop by the pharmacist’s first. Modern tonic water contains radically less quinine than its historical counterpart and many gin and tonics in the United States are made with—for shame—soda water. The next time you’re out and craving a good old fashioned gin and tonic, be sure to specify bottled tonic water.