Principles acrid

At this time is was believed that when carbonates were calcined they combined with an acrid principle from the fire to foim caustic alkalies. In 1755, however, Dr. Joseph Black (26) of Edinburgh published a famous treatise entitled, Experiments upon Magnesia Alba, Quicklime, and some other Alkaline Substances, in which he proved that carbonates lose weight during calcination and that the substance... 

Composition.—The fruit contains an alkaloid and a crys-tallizable solid oil, to both of which the name capsicine has been applied the latter body is very acrid, and constitutes the active principle of capsicum. 

Composition.—Contains, in addition to oil, an acrid purgative principle, the chemical nature of which is still unknown. 

---