Apothecaries' system of mass
The apothecaries' system of mass is an obsolete system formerly used by apothecaries (now called pharmacists or chemists) in English-speaking countries. The system was closely related to the troy system of mass, having identically sized pounds and ounces, but the two systems differed in how the ounce was subdivided.
During the 20th century, the apothecaries' system was replaced by the metric system and the SI.
| Unit | Grains | Grams |
|---|---|---|
| Pound (12 ounces) | 5760 | 373.241 72 |
| Ounce (8 drams) | 480 | 31.103 477 |
| Dram (3 scruples) | 60 | 3.887 934 6 |
| Scruple (20 grains) | 20 | 1.295 978 2 |
| Grain | 1 | 0.064 798 91 |