Gin and Tonic

• 1 part gin
• 1 part tonic water

Mix the ingredients with a squeeze of lime and serve over ice.

The cocktail was introduced by the British in India. Tonic water contains quinine, which was used to prevent malaria.

From The Restaurant at the End of the Universe, Chapter 24, by Douglas Adams:

It is a curious fact, and one to which no one knows quite how much importance to attach, that something like 85 percent of all known worlds in the Galaxy, be they primitive or highly advanced, have invented a drink called jynnan tonnyx, or gee-N-N-T'N-ix, or jinond-o-nicks, or any one of a thousand more variations on the same phonetic theme. The drinks themselves are not the same, and vary between the Sivolvian "chinanto/mnigs" which is ordinary water served at slightly above room temperature, and the Gagrakackan "tzjin-anthony-ks" which kills cows at a hundred paces; and in fact the one common factor between all of them, beyond the fact that the names sound the same, is that they were all invented and named before the worlds concerned made contact with any other worlds.

See also the list of cocktails.