A little known fact lost to history is that chlorine gas was used during WWI as a peace offering. The Allies and Central Powers used to lob canisters of it from one side to the other. The hope was that anyone with a cold—and there were many cases in those dreary, wet trenches—would start to feel better. Unfortunately, the goodwill, much like the Christmas Truce, was short lived, and the men would soon be back to trying to kill each other.
In 1924 and 1925 researchers in the CWS used bad science in an attempt to prove war gasses could be used as cures for common respiratory ailments.... In May 1924 the CWS sealed President Calvin Coolidge into a gas chamber and pumped in low levels of chlorine gas to cure his cold.