At a firing range near Berlin in mid-December 1914, Haber attended a test of artillery shells filled with tear gas, but finding the gas was too widely dispersed to have any effect, he suggested using chlorine instead, noting that it would immediately produce violent coughing; corrode the eyes, nose, mouth, throat, and lungs; and finally asphyxiate the person who inhaled it. If blown in the wind toward the enemy lines, he theorized, the gas, which was heavier than air, would sink into their trenches and either kill them there like dogs or drive the soldiers into the open, where they could easily be mowed down. The German high command embraced the gas idea as a possible super-weapon. Following a successful test demonstration outside Cologne that sealed the deal, a dinner party was planned to celebrate. But Haber’s wife, Clara Immerwahr (the first woman in her university to have earned a doctoral degree in chemistry), was deeply troubled by the immoral nature of this project, and she accused her husband of perverting science, to which he responded by branding her a traitor. That night Immerwahr took her husband’s army pistol and shot herself through the heart. The couple’s embittered youngest son, Ludwig, later wrote, “In Haber the [High Command] found a brilliant mind and an extremely energetic organizer, determined, and possibly unscrupulous.” Soon his work catapulted him to a position of great power within the German war machine, eventually earning him the title of “father of chemical warfare.”14 The budget of his institute grew fifty times larger.
Following Fritz Haber’s example, Germany’s scientists worked in close cooperation with the military as part of a highly centralized system.15 Researchers often conducted experiments on animals and humans to explore how best to treat gas casualties, and much of their study of this sort was assigned to the Kaiser Wilhelm Institute’s Department E (Pharmacology and Work Pathology), headed by toxicologist Ferdinand Flury.16 The full-scale exploration of lethal gases had begun.
Confronted with such a hideous new weapon, the British, French, and Italians immediately responded by frantically starting their own chemical warfare programs. Less than five months after the Germans’ first gas attack, the British unleashed their own chlorine cloud at Loos, but a change in the wind turned the poison back on them, causing 2,639 self-inflicted casualties (although only seven actually died) and prompting what would become a deep-seated hatred of gas on the part of many British troops.17
Not to be outdone by the Germans, the British set up a massive chemical warfare center at Porton Down. Their researchers plunged into designing new gas masks and decontamination procedures and began investigating every sort of poisonous substance known to man. The Allies also established gas schools in France to train every soldier in chemical warfare tactics. The instructors could hardly keep up with the frenzied developments in respirator equipment, warning procedures, and tutorials about all the latest gases being used by one side or the other.
Each new gas appeared more deadly than the last: phosgene (or carbonyl chloride, a compound that had originally been identified by John Davy in 1812) was said to be eighteen times more powerful than chlorine and more difficult to detect, and mustard gas, a vesicant (skin irritant), was deemed five times more lethal than phosgene. Mustard gas was considered “the most powerful casualty producing agent yet devised,” in part because “even minute traces could insinuate clothing, including rubber boots and gloves, to incapacitate victims” with huge red welts and other ailments for several days, leading to its emergence as “an almost perfect battle gas.”18 Each kind of poison offered its unique advantages and disadvantages: phosgene, for example, proved extremely deadly until soldiers learned to detect its telltale odor (like freshly cut hay) and color, and masks were devised to ward off its worst effects. Another lung and eye irritant, chloropicrin, was more difficult to defend against without gas masks containing charcoal. It took only 60 pounds of mustard gas to produce one casualty, compared to 230 pounds of lung irritant or 500 pounds of high explosives.19
Inventors devised frightful new delivery systems such as the Livens Projector and the Stokes Mortar, and starry-eyed tacticians extolled the enormous potential of air power for dropping gas bombs on hapless German troops and cities —just as their enemy plotted its own glorious triumphs. The effects of all these poisons upon the environment were simply ignored.20
One of the early innovations developed at the War Department Experimental Ground at Porton Down was a state-of-the-art “gas chamber” for testing various poison gases. Soldiers volunteered to serve as human guinea pigs (called “observers” in Porton’s terminology), subjecting themselves to any one of a range of poisonous substances that were being tested in the contraption. Typically they stood for protracted periods wearing gas masks as the vapor swirled around them, and some were required to expose areas of their skin to see how it might respond to the chemical agent.21
Cyanide gases were among the poisons studied under laboratory conditions. John Barcroft headed the unit’s physiology department. Previously French scientists had tested one such gas on dogs, which had died, but the British had tried it on goats, which survived, leaving the question of its effectiveness open to debate. Barcroft, an intrepid Quaker, decided he would personally intervene to settle the matter. One night, when everyone had gone to bed, he instructed a corporal to witness his experiment. Barcroft then flooded the gas chamber with a one in two thousand concentration of hydrogen cyanide and, without donning a mask, he entered the gas-filled chamber along with a dog. The air had a distinctive almond smell. “In order that the experiment might be as fair as possible and that my respiration should be relatively as active as that of the dog,” Barcroft wrote,
I remained standing, and took a few steps from time to time while I was in the chamber. In about thirty seconds the dog began to get unsteady, and in fifty-five seconds it dropped to the floor and commenced the characteristic distressing respiration which heralds death from cyanide poisoning. One minute out [and] thirty-five seconds after the commencement the animal’s body was carried out, respiration having ceased and the dog being apparently dead. I then left the chamber. As regards the result upon myself, the only real effect was a momentary giddiness when I turned my head quickly. This lasted about a year, and then vanished. For some time it was difficult to concentrate on anything for any length of time.22