The story of gin and tonic is pretty interesting. When british explorers were first exploring Africa, the captains made them take a crap load of quinine (to prevent malaria) and crap load of citrus fruit to prevent from getting the scurvy. Apparently, they had to intake so much quinine and so many lemons and limes, that the only way to actually get the crew to ingest this prescription was to let them drown it out with gin.

Thats where gin and tonic (and the historical lime) comes from.