“The first faint winter’s dawn was beginning to appear, and we could dimly see the occasional figure of an early workman as he passed us, blurred and indistinct in the opalescent London reek.”
—Arthur Conan Doyle, “The Adventure of the Abbey Grange”
The London fog makes its appearance as a quaint atmospheric in many a Holmes story, and became a standard of gothic detective fiction, but remembering that Doyle wrote during the coal-fueled Industrial Revolution and having lived in modern-day Beijing’s air pollution crisis, I read these references now with an extra dread.