Apothecaries' system
A traditional system of weights and fluid measures used in pharmacy, with units including grains, drachms, ounces, and fluid ounces.
Grain (unit): A small unit of mass historically used in apothecaries' and other measurement systems. The grain is the smallest commonly encountered weight unit in the system.
Apothecaries' weight system: The apothecaries' system of mass units, based on grains, scruples, drachms, ounces, and pounds. This branch defines the mass conversions used for weighed ingredients.
Roman weights and measures: Measurement units and standards used in ancient Rome, including units inherited from earlier Mediterranean systems. Some traditional medical units trace their names and ancestry to ancient measures.
Apothecaries' notation: A system of symbols and abbreviations formerly used to record pharmaceutical weights and measures. Written prescriptions once encoded these units through specialized symbols.
Apothecaries' ounce: A traditional mass unit equal to 480 grains, divided into eight drachms. It anchors the system's hierarchy of larger weight units.
Apothecaries' fluid measure: A traditional liquid-volume scale subdivided into fluid ounces, fluid drachms, and smaller units. This separate branch measures liquid quantities rather than their mass.
Medieval medicine: Medical knowledge and practice in Europe and the Mediterranean during the Middle Ages. Pharmacy's inherited measurement conventions developed through medieval medical practice.
Prescription: A healthcare provider's instruction authorizing a medicine and specifying how it should be used. Traditional prescriptions could specify doses in apothecaries' units.
Apothecaries' drachm: A traditional mass unit equal to 60 grains in the apothecaries' system. Its 60-grain definition links the grain to the apothecaries' ounce.
Scruple: A traditional mass unit equal to 20 grains, or one third of an apothecaries' drachm. It provides an intermediate subdivision between grains and drachms.