Scruple

Scruple (Lat. scrupulum, 'a small, sharp stone') was the lowest denomination of weight among the Romans, and with them denoted the 24th part of an ounce (uncia), or the 288th of a pound (libra). As a measure of surface it was also the 24th part of the uncia (see OUNCE). In Apothecaries' Weight a scruple contains 20 Troy grains, is the third part of a drachm, the 24th of an ounce, and the 288th of a Troy pound. See WEIGHTS AND MEASURES.