Joseph Merrick (1862-1890), an historical figure who was born in Leicester and died in Whitechapel, developed extreme physical deformities and was otherwise called the Elephant Man. He came to be under the care of Frederick Treves at The London Hospital.
Pang speaks Mandarin. However, most people from Hong Kong speak Cantonese.
The episode title "Pure as the Driven," is spoken by Jedediah Shine (Joseph Mawle). "And you are a fine one to speak, Edmund Upright. Pure as the driven, are you not?"