TABLES USED IN PRESCRIPTION WRITING
Reading edition
APOTHECARIES OR TROY WEIGHT.
20 Grains (Granum) (Gr. or Grs.) = 1 Scruple.
3 Scruples (Scrupulum) (Sc.) = 1 Drachm (60 Grs.)
8 Drachms (Drachma) (ʒ) = 1 Ounce.
12 Ounces (Uncia) (℥) = 1 Pound (℔)
In prescription writing the pound sign should not be used; always express large quantities by ounces.
APOTHECARIES’ LIQUID MEASURE.
60 Minims (Minimum) (M. or Ms.) = 1 Fluid Drachm.
8 Fluid Drachms (Fluid Drachma) (fl. ʒ) = 1 Fluid Ounce.
16 Fluid Ounces (Fluid Uncia) (fl. ℥) = 1 Pint.
2 Pints (Octarius) (O.) = 1 Quart.
4 Quarts or 8 Pints = 1 Gallon (congius—C.)
In prescribing liquids the abbreviation for Quarts (Qts.) is never used. If a quart is desired it is expressed as two pints (Oij).
APPROPRIATE EQUIVALENTS OF WINE UNITS IN DOMESTIC MEASURES.
Teaspoon = ʒi.
Dessert spoon = ʒii.
Table spoon = ℥ss.
Cup = ℥iv.
Tumbler = ℥viii.