In the Garden of Beasts: Love, Terror, and an American Family in Hitler's Berlin

by Erik Larson

He was Fritz Haber. To any German the name was well known and revered, or had been until the advent of Hitler. Until recently, Haber had been director of the famed Kaiser Wilhelm Institute for Physical Chemistry. He was a war hero and a Nobel laureate. Hoping to break the stalemate in the trenches during the Great War, Haber had invented poison chlorine gas. He had devised what became known as Haber’s rule, a formula, C × t = k, elegant in its lethality: a low exposure to gas over a long period will have the same result as a high exposure over a short period. He also invented a means to distribute his poison gas at the front and was himself present in 1915 for its first use against French forces at Ypres. On a personal level, that day at Ypres cost him dearly. His wife of thirty-two years, Clara, had long condemned his work as inhumane and immoral and demanded he stop, but to such concerns he gave a stock reply: death was death, no matter the cause. Nine days after the gas attack at Ypres, she committed suicide. Despite international outcry over his poison-gas research, Haber was awarded the 1918 Nobel Prize for chemistry for discovering a means of mining nitrogen from air and thus allowing the manufacture of plentiful, cheap fertilizer—and, of course, gunpowder.