XIII
CHEMICAL CONTRIBUTIONS TO PHARMACY
Chymistry. "An art whereby sensible bodies contained in vessels, or capable of being contained therein, are so changed by means of certain instruments, and principally fire, that their several powers and virtues are thereby discovered, with a view to philosophy or medicine."—Boerhaave. Quoted as a definition in Johnson's Dictionary, 1755.
Acids, Alkalies, and Salts.
Under the above title almost the entire history of chemistry might be easily comprehended. The gradual growth of definite meanings attached to these terms has been coincident with the attainment of accurate notions concerning the composition of bodies. To the ancient philosophers sour wine, acetum vinæ, or acetum as it is still called, was the only acid definitely known. When the alchemists became busy trying to extract the virtue out of all substances they produced several acids by distillation. These they called, for example, spirit of vitriol, spirit of nitre, spirit of salt, meaning our sulphuric, nitric, and hydrochloric acids respectively. They regarded everything obtained by distillation as a spirit. When the theorists came forward, Becher, Stahl, and their followers, they treated these acids as original constituents of the substances from which they were
