Was the death of baseball great Christy Mathewson at age 45 partly a result of exposure to poisonous gas in October or November 1918 in France, while serving in the same Chemical Warfare Service unit of future fellow Hall of Famers Ty Cobb and Branch Rickey?

Mathewson would die of tuberculous pneumonia in 1925.  After a 373-win, 17-year pitching career with the New York Giants, he managed the Cincinnati Reds for three seasons, including in most of 1918.  From 1919 to 1920, he returned to the Giants as a coach, until being diagnosed with tuberculosis that July.

Cobb’s 1961 book “My Life in Baseball: The True Record” claims that Mathewson suffered gas exposure in his presence. Cobb’s version has been widely accepted as true. Co-written with sportswriter Al Stump, the book describes an accident at Hanlon Field, near the French town of Chaumont. In an airtight chamber, some of those present, including Cobb and Mathewson, missed the signal to snap their protective mask into position. As a result, “sixteen men were stretched on the ground after the training exercise and eight of them died.”

The number of deaths seems way too high. That is because, by comparison, a top modern-day CWS historian has discovered just four contemporaneously reported CWS World War I deaths related to gas production or testing. Three were at the Edgewood Arsenal (now part of the Aberdeen Proving Ground in Maryland) and, as of 1918, the largest U.S. poison gas production and testing facility.  The fourth was at the American University Experimental Station in Washington.

The four fatalities are among 305 in the CWS compiled by Kip A. Lindberg, director of the U.S. Army Chemical Corps Museum at Fort Leonard Wood.  Most of the 305 died of influenza. Although Lindberg has not analyzed Hanlon Field, he said it is possible that the casualties there were non-CWS, visiting Army trainees.  Another possibility is that the eight died sometime later: over weeks, months or years.

Cobb’s book also states, “I can recall Mathewson saying, ‘Ty, when we were in there, I got a good dose of that stuff. I feel terrible.’  He was wheezing and blowing out congested matter.”

According to Jeffery K. Smart, command historian of the U.S. Army Research, Development and Engineering Command in Maryland, the stuff was probably chlorine gas and that, in some situations, it could be lethal.  Cobb, who would retire after 24 seasons in 1928 as the all-time baseball hits leader, was in Europe for just over a month, where he was assigned to the Chemical Warfare Service Technical Division’s gas training school around Chaumont.  The CWS was renamed the Chemical Corps after World War II.

Without naming Cobb, Rickey dismissed his version in his 1965 book “The American Diamond: A Documentary of the Game of Baseball.” Rickey, a Hall of Famer for having been an innovative general manager, especially of the St. Louis Cardinals and Brooklyn Dodgers, attained the rank of major in the CWS, while Cobb and Mathewson reached the lower rank of captain.

Of Mathewson’s health problems, Rickey wrote, “It was reported that he had been gassed at a gas chamber during training at Choignes, France (just outside Chaumont). That is not true. I went through the exact training with Matty (Mathewson’s nickname) and was with him immediately afterward. He had no mishap after the final field-training exposure. In fact, Matty took part in an impromptu broad-jump contest and out-leaped everyone in our group who cared to try, and by a comfortable margin. He was then thirty-eight years old.”

Two reasons for why it is hard to substantiate Cobb’s claim has to do with the administration of U.S. military records. In a 1973 fire at the National Personnel Records Center of the National Archives in St. Louis, about 80 percent of its records for those discharged from 1912 to 1960, were lost.

That said, while the St. Louis site does have plenty of descriptive “morning reports” for Army entities tagged with unit numbers, the Cobb-Mathewson-Rickey gas training school, as a “technical division,” apparently did not subdivide that way. On the one hand, according to the reference service of the U.S. Army Center of Military History, all non-combat field organizations in World War I, including the gas school, prepared morning reports. On the other hand, the National Archives in St. Louis is able to search for a morning report only if tied to a unit number.

Consistent with the school’s status as a technical division, Mathewson’s service record contains the word “casual” next to his CWS tenure at Hanlon Field. In World War I, as confirmed by the U.S. Army Center of Military History, “casual” denotes an active duty soldier not attached to a specific unit.  “CASUAL” also appears in Rickey’s CWS records at the St. Louis location, as does the shorthand “MAJ CWS CAS” (major Chemical Warfare Service casual).

An overlooked post-war affidavit claims that Mathewson suffered gas exposure in his one other subsequent military assignment, a three-month one in the 28th Division elsewhere in France. The affidavit is in a file of his military records at the National Baseball Hall of Fame Library. That work, as a divisional gas duty officer, straddled 1918 and 1919, including after the war had ended. The affidavit was attested to in September 1920, two months after the tuberculosis diagnosis. In it, former 28th Division surgeon Charles L. Shafer stated that Mathewson had been “frequently exposed to poisonous gases” while demonstrating those gases in instruction schools during his post-Hanlon Field service.

In November 1920, Mathewson’s wife, Jane, stated that he had contracted tuberculosis due to a bout of influenza upon his arrival in France, and inhalation of gas during his 28th Division service.

Two months after his death, Maj. Gen. Amos A. Fries, the second head of the CWS, was said by the St. Louis Post-Dispatch to be “of the opinion that war gas did not cause or hasten tuberculosis but in fact actually prevented it.”  Fries cited statistical studies and testimony to that effect in 1923 by the then clinical director of tuberculosis of the Veterans’ Bureau, Dr. Albert P. Francine.

In 1928, one year before retiring from military service, Fries was in Honolulu to inspect a gas regiment. A reporter for the Honolulu Advertiser was present in Fries’ hotel room afterward when he said, “The only chance Captain Mathewson had had of being gassed was limited to a whiff or two of innocuous gas that he might have received while in training.”

Based on the rebuttal in Rickey’s book, an educated guess is that if Mathewson suffered exposure, it was during his service in the 28th Division. But whether that contributed to his death — his brother Henry had died of tuberculosis in 1917 — will likely remain a mystery beyond the “fog of war.”