Alkali
a strong base, capable of neutralizing acids, so that the salts formed are either completely neutral, or, if the acid is weak, give alkaline reactions. It was formerly restricted to the hydrates of potassium, sodium, lithium, and ammonium, but now includes the hydrates of alkaline earths (baryta, strontia, and lime) and many organic substances. The term alkali usually means, in commerce, caustic soda or potash, impure, NaHO or KHO; both are used in the arts for the manufacture of glass and soap, and for many other purposes. Caustic potash is used in surgery as a cautery.