capsula

Latin capsa meant a box or case, particularly one for holding scrolls. Capsula was its diminutive: a little box, a small container. Romans used capsulae to store documents, medicines, and valuables. The capsa itself derived from capere, to take or hold, the same root that produced capture, capable, and capacity. Containment was the core idea from the start.

Medieval apothecaries adopted the term for the small containers in which they measured and dispensed medicines. By the 1600s, capsula appeared in European pharmacopeias as a specific term for a dose-sized container. The gelatin capsule -- the kind you swallow -- was invented in 1834 by a Parisian pharmacist named Joseph Gérard Auguste Dublanc and his student François Achille Barnabé Mothès, who patented the two-piece gelatin shell.

Botany borrowed the word independently. A capsule in plant anatomy is a dry fruit that splits open to release seeds. Robert Hooke used the term in this sense in the 1660s. The word was doing double duty by the 1700s: it was both the pharmacist's pill casing and the botanist's seed pod. Both meanings preserved the Latin sense of a small thing that holds something inside.

The twentieth century stretched capsule further. A space capsule (first used in the 1950s) carried astronauts. A time capsule (coined in 1937 for the Westinghouse exhibit at the 1939 World's Fair) held artifacts. A capsule wardrobe holds only essentials. Each use returns to the same Roman idea: a small container preserving something valuable.