Carbonated water (also known as soda water, sparkling water or, especially in the U.S., seltzer or seltzer water) is water containing dissolved carbon dioxide gas, either artificially injected under pressure or occurring due to natural geological processes. Carbonation causes small bubbles to form, giving the water an effervescent quality. Common forms include sparkling natural mineral water, club soda, and commercially produced sparkling water.

It is thought the first person to aerate water with carbon dioxide was William Brownrigg in 1740, although he never published a paper. Carbonated water was independently accidentally invented by Joseph Priestley in 1767 when he discovered a method of infusing water with carbon dioxide after suspending a bowl of water above a beer vat at a brewery in Leeds, England. He wrote of the "peculiar satisfaction" he found in drinking it, and in 1772 he published a paper entitled Impregnating Water with Fixed Air. Priestley's apparatus, which featured a bladder between the generator and the absorption tank to regulate the flow of carbon dioxide, was soon joined by a wide range of others.

However, it wasn't until 1781 that carbonated water began being produced on a large scale with the establishment of companies specialized in producing artificial mineral water. The first factory was built by Thomas Henry of Manchester, England. Henry replaced the bladder in Priestley's system with large bellows.

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