Graced with Attic salt

I've been doing some genealogy research. Looking through a hometown newspaper -- March 1970 -- I found this filler:

His speech was graced with Attic salt is used to mean a certain wit or vigor of style in writing in reference to the superior quality attributed to Athenian works. The Roman style was heavier, less spirited.

Anyone know what "Attic salt" means?

It is a subtle, refined wit supposedly characteristic of (ancient) Athenians.

DFG

I should, perhaps, have added that 'salt' because it added a certain 'something' to one's speech, and 'Attic' was a variation of Athenian.

DFG