The first patent Only after 1955 were the original documents for Hopkins' patent located, together with a detailed disclosure and licensing prospectus he published in 1791. These have helped reveal that the patent was important not only because it was the first of its kind but also because it was vitally linked the nation's early economy. In fact, potash was America's first industrial chemical. Potash is an impure form of potassium carbonate, mixed with other potassium salts. Until the 1860s it was derived solely from the ashes of hardwood trees and certain other plants.
Pearl ash is a less impure form of potassium carbonate.
Its name comes from its pearly color. It was essential for making soap and glass, dyeing fabrics, baking, and making saltpeter for gunpowder. Today its principal use is in fertilizers. Having greatly depleted its own timber resources, the mother country sent experts and manuals on potash making to its American colonies and otherwise encouraged potash production with tariff incentives. Around 1760 England needed several thousand tons of potash a year.