From “The Invention of Modern Gas Warfare“, at Ockham’s Razor:
One of Haber’s [Dr. Fritz Haber, inventor of gas warfare] victims was a British soldier named Fred Cayley. He was gassed in 1917. He had poor health for the rest of his life and he had to visit a doctor every week until his death in 1981. The coroner recorded that Cayley had been ‘killed by the King’s enemies’. This is the statement that would have appeared on his death certificate if he had been killed outright 64 years earlier. As far as the coroner was concerned, Cayley was as good as dead back in 1917, it was simply that he did not get buried until 1981.