Type slugs commonly used for pharmacists' typewriters: ℞ is short hand Latin for recipere aka prescription. <br /> ℥ (ounce)<br /> ℈ (scruple)<br /> Gr is for grains, an older weight measurement used before the metric system. 437.5 grains to an ounce.

https://old.reddit.com/r/typewriters/comments/1fccoqh/what_are_these_keys/