rubbing salt in the wound

[sspyder1968]

Where does the saying, 'rubbing salt in the wound' come from

[kev100]

I imagine it is from the days when sailors were flogged until their backs bled and then as further torture salt would be rubbed into the wound to make it hurt even more

[Pharlap]

I think kev100 is nearly right, but the salt was used to stop infection.