Pondera pharmaceutica

Until around 1950 European pharmacists used a special system of measuring units for mass and volume different both from the current metric one and the historical one used in commerce. The apothecaries’ system employed units inspired by those used by ancient Romans and Greeks, such as libra, uncia or drachma. Furthermore, the units were not standardized and each city of administrative unit could have its own libra, uncia or drachma. Sometimes it is thus difficult to reconstruct the recipes, even if preserved prescriptions do mention quantities employed.

list of apothecary weights in the 18th century
Pharmacopoeia Austriaca Provincialis

Apothecary weights preserved at the History of Pharmacy Collection in Cluj display markings according to this special system, the units of which were better known through their symbols:

set of apothecary weights on display in the Officina of the pharmacy museum in Cluj-Napoca

notation of the pondera in an  eighteenth-century inventory preserved at the pharmacy museum in Cluj-Napoca