With the fragment of human kidney sent in the mail to the police came a letter: "I send you half the kidney I took from one woman ... and the other piece I fried and ate ..." The writer's return address: "From Hell." It was the fall of 1888, and all of London instantly knew that the gruesome missive came from "Jack the Ripper," who had just slashed to death his fourth known victim, 43 year old Catherine Eddowes.