salt in a wound

I vaguely remember a scene from a book long ago, where someone was whipped as punishment and salt was rubbed into the wound. The whipped person eventually escaped or ran away, and then the rest of the story began.

I thought the purpose of the salt was to make the punishment hurt worse and/or to keep the wounds from healing as well or to make them scar more.

Something reminded me of that lately, so I looked it up. It turns out that historically, the purpose of putting salt on a wound was not as I thought, but rather to prevent infection.

Pour Salt In An Open Wound:

In the end, though, the phrase “salt in the wound” comes from the days when salt was rubbed into wounds as an antiseptic. During the earlier centuries, when England was establishing its navy, most sailors were forced into service. While at sea, punishment was often lashes with a cat’o’nine tails. These whippings would almost always break the skin, and salt was rubbed into the wound to prevent infection. In this way, “salt in wound” was a very literal, stinging phrase.

Nowadays, putting salt on wounds is NOT recommended:

Is It Safe to Use Salt on Wounds?
Salt in a Wound: Is it Viable for Emergency Medicine?