text: Tonic water (or Indian 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.
  History
  As early as the 17th century the Spanish used quinine from the bark of Cinchona trees to treat malaria after being shown the remedy from the Indigenous peoples of Peru, Bolivia, and Ecuador.
  In early 19th century India and other tropical posts of the British Empire, medicinal quinine was recommended to British officials and soldiers to prevent malaria, where it was mixed with soda and sugar to mask its bitter taste, creating tonic water.