In Sheridan Le Fanu's 1872 short story “Green Tea,” the Reverend Mr. Robert Lynder Jennings becomes obsessively engaged in a potentially subversive research project on ancient pagans, and finds himself experimenting with green tea as a stimulant to sharpen his mind, boost his productivity, and maintain his stamina through long, sleepless nights bent over books. One day, while riding an omnibus, Jennings sees two piercing deep red eyes staring at him, and gradually realises that they belong to a small black monkey, which was “pushing its face forward in mimicry to meet mine” (23). At first fancying the creature to be the “ugly pet” (23) of a fellow traveller, Jennings attempts to ascertain the monkey's mood, and “poked my umbrella softly towards it. It remained immovable – up to it – through it!” (23–24). Gradually, he becomes convinced of the creature's demonic nature, and this grinning, screeching vision persecutes Jennings for the rest of his days, sitting on his books and interrupting him while he studies, shrieking curses and blasphemies to drown out his prayers, soliciting him to perform evil acts, and finally, commanding him to commit suicide, which he does, slitting his own throat with a single-edged razor. In the final analysis offered by Jennings's physician and confidant, the metaphysical doctor Martin Hesselius, a significant contributing cause to Jennings's nightmarish experience was his gradual self-poisoning by green tea.