"Saleratus", potassium or sodium bicarbonate, is mentioned in the novel "Captains Courageous" by Rudyard Kipling as being used extensively in the 1800s in commercial fishing to prevent freshly caught fish from spoiling. In 1919, a U.S. Senator declared that bicarbonate of soda could cure the Spanish flu... In the midst of the debate on January 26, 1919, Senator Overman interrupted the discussion to announce the discovery of a cure. "I want to say, for the benefit of those who are making this investigation," he reported, "that I was told by a judge of a superior court in the mountain country of North Carolina they have discovered a remedy for this disease." The purported cure implied a critique of modern science and an appreciation for the simple wisdom of simple people. "They say that common baking soda will cure the disease," he continued, "that they have cured it with it, that they have no deaths up there at all; they use common baking soda, which cures the disease." - American Pandemic: The Lost Worlds of the 1918 Influenza Epidemic, Oxford University Press, March 15, 2012, page 178  Sodium bicarbonate is produced industrially from sodium carbonate: It is produced on the scale of about 100,000 tonnes/year (as of 2001). Commercial quantities of baking soda are also produced by a similar method: soda ash, mined in the form of the ore trona, is dissolved in water and treated with carbon dioxide. Sodium bicarbonate precipitates as a solid from this solution. Regarding the Solvay process, sodium bicarbonate is an intermediate in the reaction of sodium chloride, ammonia, and carbon dioxide. The product however shows low purity (75pc). Although of no practical value, NaHCO3 may be obtained by the reaction of carbon dioxide with an aqueous solution of sodium hydroxide:  Naturally occurring deposits of nahcolite (NaHCO3) are found in the Eocene-age (55.8–33.9 Mya) Green River Formation, Piceance Basin in Colorado. Nahcolite was deposited as beds during periods of high evaporation in the basin. It is commercially mined using common underground mining techniques such as bore, drum, and longwall mining in a fashion very similar to coal mining. Limited amounts of product are further obtained by solution mining, pumping heated water through previously mined nahcolite beds and reconstituting the dissolved nahcolite above ground through a natural cooling crystallization process.