Why does tonic water glow?
A brief history of quinine, fluorescence and the probable origin of the G&T.
Tonic water glows faintly in sunlight — a phenomenon that is even more apparent when it is illuminated by ultraviolet light. This glow, called fluorescence, is a special characteristic of tonic water’s main ingredient: quinine.
Quinine is what chemists call a natural product — a molecule produced by a living…