Schweppes Tonic Water 320mL is a carbonated soft drink that contains water, sugar, carbon dioxide, citric acid, natural flavorings, and quinine. Quinine is a bitter compound that comes from the bark of the cinchona tree and gives tonic water its distinctive taste. Schweppes Tonic Water is a classic mixer that can be paired with gin, vodka, or other spirits for a refreshing cocktail. It is also caffeine-free and has 130 calories per 320mL can1. Schweppes Tonic Water was first produced in 1870 and is one of the oldest brands of tonic water in the world