David H. Keller, M.D. was one of the oddest of the early science fiction writers, writing things like Revolt of the Pedestrians, in which, due to evolution in the future, the legs of car drivers have atrophied to uselessness but have almost indestructible cars and so regularly run over people who still walk, "don't worry dear" says a dad to his kid after plowing through three pedestrians "they don't feel pain like humans." and The Menace a racist novel even for that time in which mad scientists from Africa attack Americans with fake gold, madness-inducing chemicals in the water and gas that turns white folks black.