2.2.149-151 (tr. H. Rushton Fairclough):
If your wound were not relieved by the root or herb prescribed, you would give up being treated with the root or herb that did you no good.
si volnus tibi monstrata radice vel herba
non fieret levius, fugeres radice vel herba
proficiente nihil curarier.
The same, tr. Thomas Creech:
Suppose you had a Wound, and one had show'd
An Herb, which you apply'd but found no good,
Wou'd you be fond of this, increase your Pain,
And use the fruitless Remedy again?