Carbonated water, also known as soda water, sparkling water, or seltzer water, is water containing carbon dioxide, which bubbles out when the drink is depressurised. When bottled or supplied for final consumption without flavoring, it may be called club soda.

Joseph Priestley first discovered a method of impregnating water with carbon dioxide when he placed a bowl of water above a vat of fermenting beer at a local brewery in Leeds. The carbon dioxide given off by the beer, which Priestley called 'fixed air' and had been discovered and named 'mephitic air' by Joseph Black, soon became dissolved in the water. Priestley found that the impregnated water developed a pleasant sweet acidic taste and he began to offer the treated water to friends as a refreshing drink. In 1772 Priestley published a paper entitled Impregnating Water with Fixed Air in which he described a process of dripping sulphuric acid (or oil of vitriol as Priestley knew it) onto chalk in order to produce carbon dioxide and forcing the gas to disolve by agitating a bowl of water in contact with the gas.

Independently, Swedish chemistry professor Torbern Bergman succeeded in inventing another process to make carbonated water by the action of sulphuric acid on chalk in 1771, mostly to save himself money when he was ill. He was trying to imitate the naturally-occurring effervescent water that bubbles up from underground springs and was thought to be beneficial to health.

Currently, carbonated water is made by passing pressurized carbon dioxide through water. This increases the solubility; i.e., more carbon dioxide dissolves than under standard atmospheric pressures. When the pressure is reduced by opening the bottle, the gas comes out of the solution, forming the characteristic bubbles.

Carbonated water is believed by some to be good for removing stains, for example coffee stains from mugs, or stains from silver. A frequently used method of preventing red wine stains from setting in is to sprinkle salt on the stain and then apply a liberal amount of carbonated water. Schweppes manufactures unflavoured "soda water", adding to it sodium bicarbonate, thus acting as a weak antacid.

The most popular forms are flavored, and referred to as soft drinks. These are widely sold throughout the world. Major brands include Coca-Cola, Pepsi, R.C. Cola, and Dr Pepper. Many sales of these beverages are made via vending machines.

External Links

• Priestley's paper Impregnating Water with Fixed Air 1772

• Bartleby A carbonated beverage is "an effervescent drink that releases carbon dioxide under conditions of normal atmospheric pressure. Carbonation may occur naturally in spring water that has absorbed carbon dioxide at high pressures underground. It can also be a byproduct of fermentation, such as beer and some wines (see champagne). Many curative properties have been attributed to effervescent waters (e.g., aiding digestion and calming nerves), but few have been scientifically tested. The term seltzer once referred to the effervescent mineral water obtained from the natural springs near the village of Niederseltsers in SW Germany. Today, however, seltzer is simply well-filtered tap water with artificially added carbonation. Club soda is also artificially carbonated but contains other additives as well, including sodium bicarbonate, sodium chloride, sodium phosphate, sodium citrate, and sometimes light flavoring. Artificial carbonation was first introduced in 1767 by an Englishman, Joseph Priestley, and was commercialized in 1807 by Benjamin Silliman, a Yale Univ. chemistry professor, who bottled and sold seltzer water."