Blisters as Weapons of War: The Vesicants of World War I

Lewisite: A “Better” Vesicant

The Allies were pleased to be able at last to retaliate against German offensive actions with mustard, but mustard itself was not an ideal offensive agent. It was typically not deadly, and it did not take effect immediately: soldiers exposed to it did not suffer symptoms until a few hours later. These characteristics were more suited to a defensive agent; the Allies were looking for a gas that would kill soldiers immediately and send the survivors into a panicked retreat.

Besides its main CWS unit, AUES, the Research Division of the CWS was using university laboratories throughout the country to develop new poison agents. One such unit, at Catholic University of America in Washington, D.C., was headed by Winford Lee Lewis, an associate professor of chemistry at Northwestern University before he volunteered for CWS research in Washington. One of the chemistry professors at Catholic University, John Griffin, had advised the department’s first doctoral student, Father Julius Arthur Nieuwland, who went to the University of Notre Dame after receiving his Ph.D. in 1904. Griffin one day suggested to Lewis that a passage in Nieuwland’s doctoral thesis might be useful to the CWS.

The passage in the thesis, “Some Reactions of Acetylene,” described the reaction of acetylene with arsenic trichloride:

“The contents of the flask turned black. When decomposed by pouring the substance into cold water, a black gummy mass separated out, and on standing for some time crystals appeared in the aqueous solution. The tarry substance possessed a most nauseating odor, and was extremely poisonous. Inhalation of the fumes, even in small quantity[,] caused nervous depression.”

Nieuwland did not report in his thesis that his exposure to the fumes sent him to the hospital for a few days. He did, however, remark that because of the compound’s poisonous nature, he would not investigate it further.

Lewis found Nieuwland’s thesis in the chemistry’s department library and liked what he read. He subsequently reproduced Nieuwland’s experiment and then tried to purify the mixture by distillation. Unfortunately, whenever he attempted it, the mixture exploded. Lewis finally sought help from his superior, none other than James Conant, who suggested he try pouring hydrogen chloride into the mixture before trying to distill it. This worked. Distillation revealed that the mixture was composed of three similar arsenic based compounds, which became known as lewisite 1, 2, and 3, after the number of acetylene molecules bonding with the arsenic trichloride.

Lewis’s unit tested the compounds and found that lewisite 1 was the most toxic. Very small amounts caused what appeared to be immediate pain in animals, followed by blister formation and often death. The CWS liked what Lewis told them of the compound and, after naming it after him, transferred further development to the AUES, where it was supervised by Conant.

Investigating Lewisite

Conant’s task was to shepherd lewisite through the various sections within the Research Division of the CWS. These sections investigated various methods of preparation, chemical properties, and physiological actions on animals and humans (as studied by the Pharmacological Section) of new agents.

A witness to the last process, Sergeant George Temple, was interviewed by American University’s student newspaper in 1965. Temple was in charge of maintenance for the 1,500 electric motors at the AUES. When a small drop of lewisite was applied to his forearm, his skin turned deep red and developed one-inch high blisters that did not heal for eight weeks. The scars on his forearm were still recognizable when he was interviewed in 1965, and he recalled that the silver-colored blisters were excruciatingly painful.

A profile of Conant in the New Yorker in 1936 referred to the accidents occurring during the development of lewisite at the AUES: “Pipes would frequently leak or vats would boil over. A vast tub of soapsuds awaited the frenzied plunges of men on whom the horrid stuff [lewisite] had settled.” Temple in the 1965 interview also described how “hundreds and hundreds” of stray dogs were gassed at the AUES as well as some monkeys. Soldiers tied the animals to stakes, exposed them to chemical bombs, and watched them struggle and usually die. The carcasses were then shaved and dissected to determine exactly how the gases affected the animals’ physiology.

The lewisite animal tests indicated that the first symptoms were blinking and tearing of the eyes followed by nasal secretion, retching, and vomiting. Next, the animals (generally dogs) salivated excessively, and their eyes became inflamed. Their nostrils clogged, and they coughed incessantly. Many died at this stage. If the dogs continued to survive, they sneezed violently with fluid continuously flowing from their nostrils. More dogs succumbed during this period. If an animal survived beyond the fifth day, it generally recovered by the tenth day.

When liquid lewisite was applied directly to the skin of dogs, they showed immediate irritation, very different from the delay following application of liquid mustard. Redness appeared in 4 to 6 hours and blisters in 16 to 48 hours, depending on the concentration. Non-lethal doses of liquid lewisite resulted in deep burns and death of skin cells. Lethal doses caused death in one to twelve days. Based on these tests, the pharmacologists concluded that a man of average weight (70 kilograms) would be killed by the application of about one-third teaspoon of lewisite to his skin. Since this evaluation, there has been much debate about how much lewisite would actually be required to kill a human, partially because susceptibility to the compound varies significantly among animals. (For details on this and other aspects of lewisite history not discussed here, see Dew of Death: The Story of Lewisite, America’s World War I Weapon of Mass Destruction.)

Scaling Up

Once the CWS was convinced of the merits of lewisite, in July 1918, the project and Conant were transferred to Willoughby, Ohio, where Dorsey had arranged for the construction of a top-secret plant to manufacture it. Conant had been ordered to have 3,000 tons of lewisite ready for a planned offensive against the Germans in the spring of 1919. At the time CWS researchers thought that lewisite would be the gas that fulfilled the initial beliefs about poison gas, that it would bring a quick end to the war. Conant and Dorsey worked frantically to design the plant and begin production of what was hoped would be approximately 50 tons per day. Amazingly, large-scale production was under way by early November. The plant was producing not only lewisite, but also its two precursors, arsenic trichloride and acetylene. Conant received a special commendation for accomplishing the impossible in making the plant operational in so short a period of time.

By the time the armistice was signed on 11 November, the plant was probably producing 10 tons of lewisite per day, and probably 150 tons had been produced by this date. (Because of the secrecy surrounding this operation, there are many conflicting accounts of these two figures.) After the war articles about lewisite “killing power” appeared in the popular press throughout the country, with one article boasting that ten airplanes carrying the “dew of death” would have “wiped out” all life in Berlin—a “weapon of mass destruction.” Fittingly, James Conant, who was instrumental in turning both mustard and lewisite into weapons, later became chair of the National Defense Research Committee during World War II, which oversaw the development of that war’s iconic weapon of mass destruction, the atomic bomb. Thus one Harvard chemist, Conant, supervised the production of the top-secret U.S. military projects of both world wars.

A Better Gas?

Whether the compound would have actually been effective in combat has been much debated since World War I. It has had little battlefield use, though the Japanese deployed it in China during World War II. One of lewisite’s drawbacks is that it degrades in the presence of moisture. Its supporters during World War I—and even during World War II, when the United States produced about 20,000 tons—did not believe that this hydrolysis would be a significant problem. Its detractors disagreed, and experiments during World War II confirmed that hydrolysis would indeed compromise lewisite’s effectiveness in most environments because of normal humidity. In fact, although the CWS believed during World War I that lewisite was unknown to the enemy, Haber’s scientists at the Kaiser Wilhelm Institute had evaluated it and concluded that hydrolysis would make it ineffective as a weapon. Nonetheless, some countries continued to produce lewisite until recently (e.g., the Soviet Union and probably Iraq), and North Korea may still be producing the agent.

The persistence of these poison agents developed during World War I in many arsenals today has its ironic side. After working flat out to match and to surpass German production, the United States now finds that its own cities potentially face attacks from terrorists using these same weapons, with the information on how to make them readily available and requiring only minimal chemical engineering skill.

For Further Reading

Büscher, Hermann. Green and Yellow Cross: Special Pathology and Therapy of Injuries Caused by the Chemical War Materials. . . . Trans. Nell Conway. Cincinnati: Kettering Laboratory of Applied Physiology, University of Cincinnati, 1944. Originally Grün- und Gelbkreuz (Leipzig: Barth, 1932).

Guthrie, Frederick. “On Some Derivations from the Olefins.” Quarterly Journal of the Chemical Society of London 13 (1860), 129–135.

Niemann, Alfred. “Über die Einwirkung des braunen Chlorschwefels auf Elaylgas” (On the effect of the brown chloride of sulfur on olefiant gas [ethylene]). Liebigs Annalen der Chemie und Pharmacie 113 (1860), 288–292.

Senior, James K. “The Manufacture of Mustard Gas in World War I.” Armed Forces Chemical Journal 12 (Sept./Oct. 1958), 12–14, 16–17, 29.

Tucker, Jonathan.War of Nerves: Chemical Warfare from World War I to al-Qaeda. New York: Pantheon, 2006.

Vilensky, Joel A., with Pandy R. Sinish. Dew of Death: The Story of Lewisite, America’s World War I Weapon of Mass Destruction. Bloomington: Indiana University Press, 2005.