Tonic water is a carbonated soft drink in which quinine is dissolved. Originally used as a prophylactic against malaria, nowadays tonic water usually has a significantly lower quinine content and is often sweetened. It is consumed for its distinctive bitter flavor and is frequently used in mixed drinks, particularly in gin and tonic.
Under ultraviolet light, the quinine in tonic water fluoresces, as seen with this bottle of Canada Dry tonic water.
Gin and Tonic with Hendrick's Gin and Fentimans Tonic Water
Tequila and tonic cocktail
Espresso and tonic
A soft drink is any water-based flavored drink, usually but not necessarily carbonated, and typically including added sweetener. Flavors used can be natural or artificial. The sweetener may be a sugar, high-fructose corn syrup, fruit juice, a sugar substitute, or some combination of these. Soft drinks may also contain caffeine, colorings, preservatives and other ingredients.
A glass of cola served with ice cubes
Soft drink vending machine in Japan
Bubbles of carbon dioxide float to the surface of a carbonated soft drink.
Equipment used by Joseph Priestley in his experiments on gases and the carbonation of water