There are many instances where the occupants of dugouts were gassed from the gas on the shoes and clothing of men entering the dugout. Not only were occupants of dugouts thus gassed but a number of nurses and doctors were gassed while working in closed rooms over patients suffering from mustard gas poisoning. Even under the conditions of warfare existing where the Americans were generally in action, the quantity of chloride of lime required amounted to several hundred tons per month which had to be shipped from the United States. Chloride of lime was also very convenient to have at hand around shell dumps for the purpose of covering up leaky shells, though rules for handling mustard gas shells usually prescribed that they be fired and where that was not practicable to bury them at least five feet under the surface of the ground. This depth was not so much for the purpose of getting rid of the gas as it was to get the shell so deep into the ground that it would not be a danger in any cultivation that might later take place.
Mustard Gas in Cold Weather
Much was learned toward the end of the war about ways of getting through or around areas infected with mustard gas. For instance, if mustard gas be fired when the weather is in the neighborhood of freezing or somewhat below, it will remain on the ground at night with so little evaporation as not to be dangerous. The same will be true during the day time if the weather is cloudy as well as cold. If, however, the days are bright and the nights cold, mustard gassed areas can be safely crossed by troops at night provided care is taken in brush and bushes to protect the feet and clothing from the liquid splashed on bushes. If the sun comes out warm in the morning such areas may be quite dangerous for three to four hours following sun-up and indeed for the greater part of the day. Quite a large number of casualties were ascribed to this fact in the heavy attack on the British front west of Cambrai just prior to the great German drive against Amiens, March 21, 1918.
Degassing Units
Since mustard gas has a greatly delayed action it was found that if men who had been exposed to it could be given a thorough bath with soap and water within a half hour or even a full hour, the mustard gas burns would be prevented or very greatly reduced in severity. Accordingly degassing units were developed consisting essentially of a 5 ton truck with a 1200 gallon water tank, fitted with an instantaneous heater and piping to connect it to portable shower baths. Another truck was kept loaded with extra suits of underclothing and uniforms. These degassing units were to be provided at the rate of two per division. Then, in the event of a mustard gas attack anywhere in the division, one of these units would be rushed to that vicinity and the men brought out of the line and given a bath and change of clothing as soon as possible. At the same time they were given a drink of bicarbonate of soda water and their eyes, ears, mouth and nasal passages washed with the same.
Protecting Food from Mustard Gas
It was very early learned that mustard gas, or minute particles of the liquid gas settling on food, caused the stomach to be burned if the food were eaten, just as the eyes, lungs and skin of the body are burned from gas in the air. This made it necessary then to see that all food liable to exposure to mustard gas attacks was protected, and tarred paper for box linings or tops was found by the Gas Service to furnish one of the cheapest and most available means of doing this.
Alarm Signals
Numerous, indeed, were the devices invented at one time or another with which to sound gas alarms. The English early devised the Strombos horn, a sort of trumpet operated by compressed air contained in cylinders carried for that purpose. Its note is penetrating and can be heard, under good conditions, for three or four miles. When cloud gas attacks, which occurred only at intervals of two to four months, were the only gas attacks to be feared, it was easy enough to provide for alarm signals by methods as cumbersome and as technically delicate as the Strombos horn.
With the advent of shell gas in general, and mustard gas in particular, the number of gas attacks increased enormously. This made it not only impossible, but inadvisable also, to furnish sufficient Strombos horns for all gas alarms, as gas shell attacks are comparatively local. In such cases, if the Strombos horn is used to give warning, it causes troops who are long distances out of the area attacked to take precautions against gas with consequent interference with their work or fighting.