Definition:Apothecaries' Ounce/Mistake

Source Work

 * The Dictionary
 * $24$
 * $24$


 * The Dictionary
 * $24$
 * $24$

Mistake

 * ... Also $24$ scruples in an ounce, and ...

It is not made clear that this is an apothecaries' ounce, not an ounce avoirdupois, which is some $10\%$ lighter.