Fritz Haber
People can also use ammonia to make explosives and poisons.  During World War I, Haber studied how to use his inventions for weapons.  Experts say Germany lasted one year long in World War I than it would have without Haber's poisons and explosives.  Haber said he did not think killing a soldier with poison gas was any worse than by letting the soldier bleed to death.  During World War I, Haber's first wife killed herself.