Quinine, a key ingredient in tonic water, was sourced from the cinchona tree, primarily found in South America but later cultivated in British-ruled India.

Tonic water, which contained quinine, was developed to make quinine consumption more palatable and effective in preventing malaria.

The term 'Indian' was likely attached to tonic water as a nod to its origin and to highlight its association with the regions where quinine production was prominent.

The refreshing combination of gin and 'Indian' tonic water became popular among British colonists in India, further cementing the name.

Over time, the name persisted and is now commonly used to describe tonic water, even though its historical connections to India have become less relevant.

Today, 'Indian' Tonic Water remains a staple in bars and households worldwide, and its name serves as a reminder of its rich history.