Quinine water is an older name for what is more commonly referred to these days as tonic water. Quinine water is popular throughout the world, and is the basis for some popular mixed drinks, including the Gin and Tonic. It is given its name because it has a small amount of quinine, a crystalline alkaloid, in it.

Quinine water has its roots in the early 17th century. The story goes that the Countess of Chinchon, living in Peru, came down with a dreadful case of malaria. As she lay close to death, her husband begged the local Incas for some sort of a cure. They made her a tonic, which was primarily the ground up bark of the Quinquina tree that made its home in the Andes. She recovered, and the Spanish saw that they had discovered a remedy for the dreadful scourge of malaria.

The bark of the Quinquina tree was exported in massive amounts to Europe. It became a sort of miracle drug, even curing King Louis XIV of malaria. But because of trade restrictions the seeds themselves were not allowed out of Peru. Because there was a limited amount of Quinquina bark available, prices soon went through the roof, and eventually smugglers got some seeds out of Peru and to Holland. The Dutch then set up massive Quinquina plantations in Java, and for the next few centuries supplied most of the world’s quinine.

British soldiers were issued quinine medicine to take every day in places like India to ward off malaria. The medicine was bitter, and certainly no fun to drink. At some point, enterprising British officers began mixing their quinine medicine with soda water, making the first quinine water. They then mixed this quinine water with a big of sugar and gin, to further mask the taste of their medicine, and in the process created the Gin and Tonic.

Originally, quinine water contained a large amount of quinine for medicinal purposes. As it became less and less important, however, to ward off malaria, the amount was reduced. Most modern quinine water contains a negligible amount of quinine. In the United States it is limited by law to 83 parts per million, which is less than one half of one percent of the amount found in historical quinine water.

Because of its physical properties, quinine becomes fluorescent when exposed to ultraviolet light. This means that quinine water, placed under an ultraviolet light, will glow as though it has its own internal light. In fact, quinine is so sensitive that it will turn slightly fluorescent even when exposed to normal sunlight, because of the small amount of ultraviolet light hitting it.

Since World War II, when the Japanese interrupted the world’s flow of quinine water from Java, synthetic quinine has replaced quinine bark in most of the world’s quinine water. The difference between natural and synthetic quinine is negligible, but a few boutique companies have begun producing quinine water using actual bark, touting it as a more natural and healthier alternative.