Theories
Many other theories exist as to the origins of the Rx. One of my favourites, from the book Devils, Drugs and Doctors, written 1931, plays on the fact that the Rx isn’t a normal ‘R’ and an ‘x’ but more a symbol in which the italic R leg hangs down below the line with an X line through it…
Rx
“Is an invocation to Jupiter, a prayer for his aid to make treatment effective…sometimes in old medical manuscripts all the R’s occurring in the text were crossed”
Roman God
In other words, the Rx symbol was a corruption of the ancient symbol for the Roman god Jupiter. Astrology fans will recall that this symbol has a very similar crossed leg at the bottom right. Whatever the history, just for a laugh, ask your local pharmacist if he/she knows about the origins of Rx.