Did You Know? Tonic water can glow in the dark

Tonic water is best known for adding a little bite to cocktails, though it has a hidden talent: It glows when exposed to ultraviolet light. While modern tonic waters often include citrus flavors or sweeteners to ease their bitter taste, the mix is traditionally crafted from just two ingredients — carbonated water and quinine, the second of which is capable of illumination. Quinine’s ability to glow, technically called fluorescence, only occurs when the substance is exposed to the right conditions, particularly when its molecules absorb invisible ultraviolet light (such as that projected by a black light). The excited molecules then quickly release that energy, which appears as a blue hue to the human eye in a darkened room.

Though tonic water is now a bar cart staple, its initial purpose wasn’t enjoyment — it was to prevent and treat malaria. Quinine, which comes from the bark of the South American cinchona tree, was first used by the Indigenous Quechua people as a cure-all for stomach ailments; by the 1600s, Europeans had documented its fever-reducing properties. In the 1700s, Scottish doctor George Cleghorn discovered it could also effectively treat malaria. As the only known treatment for nearly 300 years, quinine’s bitter flavor was paired with water to create a “tonic,” and distributed to British soldiers stationed in India and other malaria-prone regions. Some historians believe soldiers began adding the medication to gin and other alcohols to make the bitter flavor more palatable, eventually creating the “gin and tonic” drink we know today. However, other researchers suggest it wasn’t until the 1860s that the classic drink emerged, served to victorious patrons at horse racing tracks in India.

Media Release/InterestingFacts.com