The
apothecaries' system of weights is a historical system of
mass units that were used by
physicians and
apothecaries for medical recipes, and also sometimes by scientists. The English version of the system is closely related with the English
troy system of weights, the
pound and
grain being exactly the same in both. It divides a pound into 12 ounces, an ounce into 8
drachms, and a drachm into 3
scruples or 60 grains. This exact form of the system was used in the
United Kingdom; in some of its former colonies it survived well into the 20th century. The apothecaries' system of measures is a similar system of
volume units based on the fluid ounce. For a long time, medical recipes were written in
Latin, often using special symbols to denote weights and measures.