Around the year 1775 industrial age chemists discovered that if you expose pearlash (potassium carbonate) to carbon dioxide gas the result was potassium bicarbonate, a compound that’s about twice as potent as regular old pearlash. The creation was dubbed “saleratus”, a Latin word meaning “aerated salt.” The discovery prompted an American entrepreneur by the name of Nathan Read to try making the stuff, which he did by suspending pearlash over vats of fermenting rum which produce — you guessed it — CO2. Very clever indeed. Read’s saleratus came on the market in 1788. But the stuff never really caught on as a leavener, mostly because it wasn’t terribly pure and hence not very reliable.