QUID PRO QVO, or QUI PRO QVO, is also used in physic to
express a mistake in the physician's bill, where quid is writ-
ten for quo, that is, one thing for another; or of the apothec-
ary in reading quid for quo, and giving the patient the
wrong medicine. Hence the term is in general extended
to all blunders or mistakes committed in medicine, either
in the prescription, the preparation, or the application of
remedies.