Lime soda

A lime soda was the drink that the Tenth Doctor ordered upon arriving at a garden party at Eddison Manor in 1926, at the same time that Donna Noble ordered a sidecar. (TV: The Unicorn and the Wasp)

Behind the scenes
Though largely replaced today by lemon-lime variants like $®$, $®$ and other easy-to-buy brands, lime soda would have been something the staff of Eddison Manor would have had to have made from scratch, probably following a recipe like this one.