Attic salt

Attic + salt; a calque of Latin sāl Atticus or sāl Atticum. In classical times “salt” was a frequent metaphor for “wit”.

• "His [Lucan's] wit, ſays Ablancourt, was full of urbanity, that Attic ſalt which the French call fine raillery; not obſcene, not groſs, not rude, but facetious, well-mannered, and well-bred."
• "Koznyshev, who knew better than anyone how at the end of a most abstract and serious dispute unexpectedly to administer a grain of Attic salt and thereby to change his interlocutor's frame of mind, did so now."
• "But Attic salt is not the sole preservative against the decay that threatens all human writings; nor can mere eloquence rekindle the ashes of a dead controversy."