The name of which type of soup is sometimes used to describe thick fog?

pea soup reminds me of the movie, the exorcist.

toe jam, still love pea soup despite watching the exorcist, which still scares the living daylights out of me. In saying that Linda Blair played the part so well.

Not only London was affected by it apparently my home town of Stoke used to have it due to the smoke bellowing from the bottle kilns, of which not many remain, those that do are listed buildings.

Looking out my window, I see some pea soup now. Dam global warming...

Stanley R.Camiguin , what?

It took the Clean Air Act quite a few years to make a difference. In the early 60s 'smog' as it was often called, was quite frequent in London and absolutely filthy.