On the night of September 1, 1944, Aline Kearney went to bed alone in her small Mattoon, Illinois, home while her husband worked a late shift at the factory, leaving her windows open in the late-summer heat.
She noticed a sweet, flowery scent drifting in — then realized, with growing alarm, that it was not flowers. Her legs went numb. She could not move them. By the time her husband arrived home, she was in genuine physical distress. The next morning, the Mattoon Daily Journal-Gazette ran the story under a headline that would change the town's September: a mad gasser was loose in Mattoon, spraying paralyzing gas through open windows at night. Over the next twelve days, twenty-five more households reported the same experience. No gasser was ever found, because the scientific consensus that emerged from the case held that there was never a gasser to find. What Mattoon had experienced was one of the first mass hysteria events in American history to be formally documented in an academic journal — a case so thoroughly studied that it became a standard reference in the psychology of collective fear for the next eighty years.
Background: A Wartime Town on Edge
In September 1944, Mattoon was a town of roughly 16,000 people in east-central Illinois, its economy running on the Atlas Imperial Decorating Company and the Dewey and Almy Chemical Company, both operating wartime production shifts. A significant portion of its men were overseas. Women worked factory shifts, managed households alone, and followed war news that offered, in the summer of 1944, a relentlessly uncertain picture of what the coming months would bring. The local newspaper had recently reported that police were searching for a Nazi who had escaped from a prisoner-of-war camp near Peoria. Prowler sightings around town had been common enough to generate their own undercurrent of anxiety.
This was the community into which Aline Kearney's story landed. Her husband Bert, who had not been in the bedroom when the incident occurred, provided police with a description of a figure he claimed to have seen outside — tall, thin, dressed in dark clothing, wearing a tight-fitting cap. His wife, notably, had not described seeing anyone. Bert Kearney's account of the Mad Gasser's appearance became, by default, the description that subsequent victims would draw on when asked what they had seen or heard outside their windows. The template was established on night one.
How the Contagion Spread
The Mattoon Daily Journal-Gazette's headline on September 2 read "Anesthetic Prowler on Loose." Within days, the Associated Press had picked up the story and distributed it nationally, framing Mattoon as the site of an active criminal case involving a mysterious chemical weapon. Local police increased nighttime patrols. State investigators were called in. Citizens organized neighborhood watches. The paper offered a reward. Every element that had accelerated the Halifax Slasher panic six years earlier in England — a named, rewarded threat, media amplification, community vigilance, and a population already primed by background anxiety — was present in Mattoon in the first week of September 1944.
Reports clustered in a pattern that investigators later found revealing. Ninety-three percent of the reported victims were female, predominantly of lower socioeconomic status. Symptoms varied but followed a consistent template: a sweet or sickly odor, followed by nausea, tingling or numbness in the extremities, and temporary leg weakness. Several husbands present during the same alleged attacks reported similar symptoms, but were not formally counted as victims because they were not the ones who had filed the initial complaint — a detail that sociologist David L. Miller later flagged as one of the more striking indicators of selective reporting at work. On September 12, after 33 people had reported exposure in 12 days, Mattoon's police chief C.E. Cole released a statement: there was no man sneaking around town. Wind shifts from a local war production plant had likely caused industrial fumes to pass through open windows on warm nights, and at least a substantial fraction of subsequent reports were the result of suggestion.
| Feature | Halifax Slasher (1938) | Mattoon Mad Gasser (1944) |
|---|---|---|
| Duration of panic | ~2 weeks (Nov 16 – Dec 2) | ~12 days (Sep 1 – Sep 12) |
| Total reports | 21 reported attacks | 25–35 reported gassing incidents |
| Primary victims | Mostly women; some men | 93% female (Johnson, 1945) |
| Named threat | "The Halifax Slasher" | "The Mad Gasser" / "Phantom Anesthetist" |
| Official conclusion | Scotland Yard: no attacker existed | Police chief + Johnson 1945 study: mass hysteria |
| Physical cause proposed | None; self-inflicted wounds | Industrial fumes from local war plant (wind shifts) |
| Academic study | Referenced in sociology literature | Johnson (1945), Journal of Abnormal and Social Psychology |
| Minority counterargument | Not significantly maintained | Farley Llewellyn theory; some researchers dispute full hysteria conclusion |
The Johnson Study and Its Legacy
What distinguished Mattoon from earlier mass hysteria episodes was the speed with which it attracted rigorous academic attention. In 1945, Donald M. Johnson published a field study in the Journal of Abnormal and Social Psychology, characterizing the episode as a textbook example of mass hysteria shaped by rumor and suggestibility. Johnson had visited Mattoon in the weeks following the scare, interviewed residents, reviewed police reports, and mapped the geographic and temporal distribution of reported cases. His paper, titled "The 'Phantom Anesthetist' of Mattoon: A Field Study of Mass Hysteria," became a foundational reference in the psychology of collective delusion, cited in textbooks for decades afterward. In 1959, psychologist James P. Chaplin independently reviewed the case and reached the same conclusion.
Johnson's analysis identified several specific mechanisms. The initial report established a symptom template — sweet odor, leg weakness, nausea — that subsequent reporters reproduced almost verbatim. Cases clustered in time and geography in ways that tracked media coverage rather than any physically plausible gas dispersal pattern. Reports of symptoms appeared in individuals who had only read about the incidents in the newspaper, without any plausible chemical exposure, including several journalists who developed headaches while covering the story. The absence of any physical evidence — no containers, no chemical residue, no consistent forensic findings — further supported the mass hysteria interpretation. Police Chief Cole's industrial fumes explanation accounted for the earliest, most plausible cases; Johnson's study accounted for everything that followed.
Theories and Explanations
The mass hysteria explanation, supported by Johnson's 1945 study, Robert Bartholomew's later sociological work, and the formal conclusions of Mattoon's police and state investigators, holds that the episode broke down into three overlapping components: a small number of early cases involving genuine sensory confusion with industrial fumes from the Atlas and Dewey plants; a larger number of subsequent cases driven by suggestion, anxiety, and symptom template adoption; and a community-wide state of heightened vigilance in which any unusual smell or physical sensation was automatically attributed to the phantom gasser. The 93 percent female victim rate, Johnson argued, reflected both the social isolation of women whose husbands were away and their greater susceptibility to the specific kind of suggestion-driven anxiety that wartime conditions produced.
A minority of researchers, most prominently Scott Maruna in a 2003 book, have argued that a real perpetrator existed: Farley Llewellyn, a local man with a chemistry background and alleged personal grievances against some of the reported victims' families. Maruna's theory has not gained mainstream acceptance among historians or psychologists, partly because it requires attributing a highly selective, geographically precise chemical dispersal operation to a single amateur with no known motive to target the specific households affected, and partly because the symptom patterns and geographic clustering fit the mass hysteria model considerably better than any chemical attack model. Robert Bartholomew, whose work on epidemic suggestion was cited in the Halifax Slasher analysis, has described the Mattoon case as one of the most thoroughly documented examples of anxiety-driven symptom contagion in the twentieth century.
The Curious Connection
Mattoon's Mad Gasser sits alongside Halifax's Slasher as a structural twin separated by six years and an ocean: the same two-week timeframe, the same media amplification, the same named phantom, the same community watch patrols, and the same eventual official conclusion that the threat was not real. The difference is that Halifax produced a final police tally that categorized each report individually, while Mattoon produced an academic paper that mapped the contagion's mechanism across a population — and it is the Mattoon paper that became the founding document for the scientific study of mass psychogenic illness as a field.
What Johnson's 1945 study established, and what every subsequent study of collective hysteria has refined, is the precise sequence by which a named, publicized fear converts background anxiety into physical symptoms in a population that is already primed to experience them. Mattoon's wartime context — husbands absent, chemical warfare a genuine contemporary reality, local factories producing genuine industrial fumes — provided the anxiety. The newspaper headline provided the template. And the template, once established, reproduced itself through thirty-three households in twelve days without requiring any gasser at all, demonstrating for the first time in a formally documented way that a phantom can be as physiologically effective as a real threat, provided the community believes in it with sufficient collective intensity.
FAQ
Who was the Mad Gasser of Mattoon?
The Mad Gasser of Mattoon was a name given to a supposed criminal who allegedly sprayed paralyzing gas through open windows in Mattoon, Illinois, during September 1944. Police investigations and a 1945 academic study concluded that no gasser existed, and that the reports were a combination of genuine industrial fume exposure in early cases and mass hysteria in the majority of subsequent reports.
What symptoms did people report from the Mad Gasser?
Reported symptoms included a sweet or sickly odor, nausea, vomiting, tingling or burning sensations in the limbs, and temporary leg weakness or paralysis. These symptoms are consistent with anxiety-driven psychogenic reactions as well as with low-level industrial solvent exposure, which is why both explanations have been proposed for the earliest cases.
What did Donald Johnson's 1945 study conclude?
Johnson's study, published in the Journal of Abnormal and Social Psychology, concluded that the Mattoon episode was a textbook case of mass hysteria in which initial reports established a symptom template that spread through the community via suggestion and media coverage. He noted that 93 percent of victims were female and that cases tracked newspaper coverage rather than any physically plausible gas dispersal pattern.
Was there a real gas or chemical involved in the Mattoon incidents?
Mattoon's police chief proposed that wind shifts carried industrial fumes from local war production plants through open windows on warm nights, accounting for the earliest reported cases. State and federal investigators found no evidence of a chemical weapon or deliberate gassing device, and subsequent reports showed no consistent chemical signature.
Is the Mattoon Mad Gasser connected to any real person?
In 2003, researcher Scott Maruna proposed that a local man named Farley Llewellyn, who had a chemistry background, was responsible. This theory has not gained mainstream acceptance, as the symptom patterns and geographic clustering of reports fit the mass hysteria model better than any single-perpetrator chemical attack scenario.