APOTHECARIES' WEIGHT

traditional European system of weight used for the measuring and dispensing of drugs and based on the grain, scruple (20 grains), dram (3 scruples), ounce (8 drams), and pound (12 ounces). The apothecaries' grain is equal to the troy and avoirdupois grains and represents 15,760 part of the troy and apothecaries' pound and 17,000 part of the avoirdupois pound. One apothecaries' pound equals approximately 0.82 avoirdupois pound and 0.37 kilogram. Apothecaries' weight was used officially in both the United States and Great Britain until 1858. In that year, under the authority of the Medical Act, Great Britain adopted the avoirdupois system for dispensing medicines. Apothecaries' weight is still common in the United States. In recent years, however, the metric system has gained in use for dispensing medicines.