Isolation, structure, and partial synthesis of an active constituent of hashish.

Mechoulam and Gaoni showed that the active ingredient of "one of the most widely used illicit narcotic drugs," the flowering tops of Cannabis sativa, is "pure tetrhydrocannabinol" (THC).  This they called the "psychotomimetically active resin of the female flowering tops."

(Thanks to Juan Weiss for this reference and its interpretation.)