Such chemicals as the Chemical Warfare Service did sell after the armistice brought good prices. The prices of many chemicals went up after the armistice, and the Chemical Warfare Service profited accordingly. The Service made a profit of 100 per cent on the phosgene it sold and also found a good market for its chlorine.
Among the reserves stored at Edgewood was a considerable quantity of the felt which was developed by Americans as a protection against arsenical smoke, a deadly chemical never given a trial in the field of battle, but regarded as an inevitable development in the expected campaign in 1919. The production of toxic smoke was one of the most interesting phases of the history of chemical warfare in the World War. The candles which projected this smoke were perhaps the most appalling weapon devised by any of the belligerents during the conflict, and the armistice interrupted an Anglo-American project, well under way, to asphyxiate the Germany Army with them in the spring of 1919. This development was one of the deepest military secrets both in England and the United States. Except for the French, not even the other Allies were admitted to the secret.
The smoke candles employed an arsenical compound known as diphenolchlorarsine. In the laboratory this was not a new substance—in fact, none of the war gases actually used in the field was a new development; and of projected poisons, so far as is known, only the deadly Lewisite, the invention of Captain W. Lee Lewis in the Chemical Warfare Service’s laboratory in Washington, was a new chemical creation evolved specifically for use in war.[11] The other war gases had all been known to organic chemistry, some of them for many years. So with diphenolchlorarsine. It was first produced in Germany in the last century, and the Germans also originated its use as a military weapon.
The Germans produced and used diphenolchlorarsine as a solid. The substance was put into glass bottles, which, in turn, were inserted in the T. N. T. filler of shell. The explosion pulverized the chemical into a fog which had the advantage of being able to pass through the cotton baffles in the canister of an ordinary gas mask. This fog was highly irritating to the membrane of the nose and throat and caused sneezing, which prevented a soldier gassed with it from putting on his mask, so that he was left a victim to more lethal gases fired simultaneously.
The British secured “dud” shell containing diphenolchlorarsine and at once recognized this chemical as potentially much the most fatal substance yet brought out in chemical warfare. But it was evident that the German was not using it properly, in such a way as to release its full toxic effect. The question was how to atomize diphenolchlorarsine much more finely. British chemists and mechanical engineers eventually succeeded in producing the substance in candles which burned and cast out dense smoke. This smoke was diphenolchlorarsine so finely divided that the American gas mask, the most effective mask of all, was utterly powerless against it. The smoke particles passed freely through the baffles; and, since the particles were minute solids and not true gas at all, they were unaffected by the gas-absorbing charcoal and lime of the mask canister.
Every masked experimenter gassed by this smoke declared that a mask was worse than no protection at all. It is notable, too, that every one gassed, without knowing that he was merely reiterating what others before him had said, declared that, if he had not been able to escape quickly from the concentration, he would have shot himself rather than endure the agony longer. As to the persistence and diffusibility of the smoke, at one demonstration when two candles were burned in a desolate spot in England, civilians were slightly gassed in a village several miles away.
So much for the substance which outdid any of the horrors of the most horrible of all wars. But the weapon was useless unless protection against it could also be developed. America invented the protection—thick felt which was a textile triumph in that it absolutely caught and held the smoke particles, yet permitted fairly easy breathing through itself. The plan was to issue this felt in small pieces which the soldiers could wrap around their canisters, in order that all inhalation should be through the felt. The felt-wrapped canister would then be placed back in its knapsack. In the joint project, we were to produce the protective felt and the British the candles. The British had ordered several million of these and were actually producing them in large quantities at the time of the armistice. By that date the American mills were turning out the felt by thousands of yards, and our Chemical Warfare Service was also planning a factory in which to produce diphenolchlorarsine candles. All this activity was an intense secret in both countries. The program was being directed at a certain week in the spring of 1919, when, at a favorable hour, the troops on our side having quietly been protected against the smoke, it was proposed to fire the candles everywhere along the front. The gas warfare organizations of Great Britain and America confidently expected that when that lethal infusion had disappeared, the German Army would practically have ceased to exist, and the war would be over.
There is reason to believe that the German also realized the inefficiency of diphenolchlorarsine when fired in shell and had followed an independent line of development which led him to the production of candles. It is asserted that such candles were made in Germany before the armistice. It is doubtful, however, whether the German succeeded in developing a protection against the smoke.
After the armistice our Chemical Warfare Service continued an independent development of arsenical smoke. The problem was a mechanical one. The chemical is driven off as smoke by means of heat. If the heat is too great, the substance will burn and be changed into non-toxic compounds. If the heat is too mild, the smoke will not be thrown off efficiently. This problem we have solved.
Mention should be made also of that other chemical secret of the war, Lewisite. In one sense Lewisite can be termed a development of mustard gas, for the laboratory process of making mustard suggested to Captain Lewis certain analogous chemical reactions, out of one of which came the hitherto unknown liquid which was named after him. Like mustard, Lewisite is a so-called vesicant, a substance which blisters the skin, but it is much more powerful; for, whereas mustard gas merely burns, Lewisite is absorbed through the skin into the system. Three drops of this chemical placed on the belly of a rat will kill the animal in two or three hours, and it is believed that this would be the effect of a similar quantity sprinkled on the skin of a man. Like mustard, too, Lewisite gives off fumes slowly, and these fumes have a burning, deadly effect.