Thanks to Usual John for sending this in.

John points out “Some commenters on GoComics suggested that this strip refers to Charles de Gaulle’s practice, at this time, of exchanging U.S. dollar reserves for gold. While the timing works for this 1966 strip, I don’t see how it leads to a joke.”

My question back then was, always if you can buy bouillon cubes at the supermarket in chicken or beef, why not gold?