Hiroshima_ The World's Bomb - Andrew J. Rotter [11]
The Germans had been thinking about chemical weapons since at least the previous year. From the first, German military officials had involved academic and industry chemists in the quest for an agent that would disorient and damage enemies dug into trenches on both fronts. They experimented in the fall of 1914 with a compound that caused violent fits of sneezing, pouring it into howitzer shells and launching them at the French at Neuve Chapelle in October. The compound dispersed poorly and had no apparent effect on the battle, and the shortage of shells and launchers made continued experiments unattractive. The eminent chemist Fritz Haber found a solution: disperse chlorine gas from metal cylinders, creating a toxic cloud that would settle over enemy positions. The German command agreed to try this. The generals recruited scientists and soldiers to serve as forward observers—that is, to find the most favorable positions from which to launch the gas cloud. Six thousand cylinders were opened simultaneously that April afternoon. The cloud at first looked white, then intensified to yellow and green as the amount of chlorine in it rose, drifting higher and moving south and west over French and Algerian posts. The affected soldiers broke and ran.14
Among those Germans sent to plan the attack was Otto Hahn, already well known for his work on radiation with Ernest Rutherford in Montreal. Haber pressed Hahn into service in the name of science and loyalty to the German state. By his own account, Hahn was not so sure, objecting that the use of gas would violate the Hague Convention of 1899, which proscribed the use of projectiles to diffuse ‘asphyxiating or deleterious gas’. Haber responded, first, that the French had already started it, having filled rifle cartridges with tear gas (a dubious claim when Haber made it, in January 1915), and, more important, that the use of gas would ultimately save lives on all sides because it would end the war sooner. It was also technically true that the release of a gas cloud did not involve launching projectiles. Hahn evidently accepted this logic. ‘I let myself be converted’, he remembered, ‘and threw myself into the work wholeheartedly.’ He remained involved in chemical warfare, and was called a ‘gas pioneer’, until the armistice—even after Haber had confided to him that he thought the war was lost.15
The Germans continued to develop new chemical compounds and new ways to deliver them. Shells came largely to replace clouds released from cylinders; chlorine was succeeded by phosgene and chloropicrin, harder than chlorine to detect and more destructive. In the summer of 1917 they fired at Ypres shells marked with a yellow cross and filled with mustard gas, which smelled like horseradish and was, according to one commentator, ‘the war gas par excellence for the purpose of causing casualties’. Men were blinded, in some cases permanently, about seven hours after exposure to it. German use of gas increased especially on the Eastern Front, where prevailing winds favored the emissions and where the Russians were slower than the Western Entente combatants to develop effective gas masks. Hahn helped to coordinate a chlorine and phosgene attack against Russians in Galicia in June 1915. The Russians were taken by surprise, and, as Hahn advanced with German troops, he found their enemies in extremis. ‘We tried to use our own respirators to help some of them, to ease their breathing, but they were past saving,’ Hahn wrote. His conscience prickled. But he and Haber were hardly alone in the work: they were joined by several noted chemists and the physicist James Franck, who would later join the Manhattan Project and urge that atomic bombs not be dropped