Several texts on the history of chemical warfare mention the story that in May 1924 the U.S. Army Chemical Warfare Service (CWS) treated President Calvin Coolidge for a severe cold with chlorine. For example:
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. After 45 minutes inside the chamber, Coolidge emerged and returned to work.
(T. I. Faith, Under a Green Sea: The US Chemical Warfare Service 1917–1929, Dissertation submitted to The George Washington University, May 18, 2008)
In all relevant texts that I have found, the original source of this story is the newspaper article “Army’s Chlorine Gas Helps Coolidge’s Cold; He Spends 45 Minutes in Air-Tight Room”, The New York Times, May 21, 1924, Page 1.
The CWS organized and financed various publicity campaigns in order to prove their importance; however, such a potentially dangerous publicity stunt seems to be excessive since it was known that exposure to chlorine could cause damage to one’s health, including delayed pulmonary oedema. This makes me doubt whether the story is absolutely true. Could the newspaper article be exaggerated in any way? Are there any other references for this story?