\begin{definition}[Definition:Apothecaries' Weights and Measures/Mass/Drachm]
The '''drachm''' is an apothecaries' unit of mass.
{{begin-eqn}}
{{eqn | o = 
      | r = 1
      | c = '''drachm'''
}}
{{eqn | r = 3
      | c = scruples
}}
{{eqn | r = 60
      | c = grains
}}
{{eqn | r = 3 \cdotp 89
      | c = grams
}}
{{end-eqn}}
\end{definition}