For several centuries, people have debated whether human beings can spontaneously combust, or burst into flames without being ignited by an external source. Though the first known accounts of spontaneous human combustion (SHC) date all the way back to 1641, the phenomenon gained wider exposure in the 19th century after popular author Charles Dickens used it to kill off one of the characters in his novel “Bleak House.”

When critics accused Dickens of legitimizing something that didn’t exist, he pointed to research showing 30 historical cases. More recently, cases of SHC have been suspected when police and fire department officials have found burned corpses with unscathed furniture around them. For instance, an Irish coroner ruled that spontaneous combustion caused the 2010 death of 76-year-old Michael Faherty, whose badly burned body was discovered near a fireplace in a room with virtually no fire damage.

Because the human body is composed mostly of water and its only highly flammable properties are fat tissue and methane gas, the possibility of SHC being an actual phenomenon seems remote. Many scientists dismiss the theory, arguing that an undetected flame source such as a match or cigarette is the real culprit in suspected cases. Typically, deceased victims are found close to a fire source, and evidence suggests that many of them accidentally set themselves on fire while smoking or trying to light a flame.

On the other hand, believers point to the fact that the human body has to reach a temperature of roughly 3,000 degrees in order to be reduced to ashes. Unless SHC were a genuine factor, it seems impossible that furniture would not burn as well. Proposed causes of the supposed phenomenon include bacteria, static electricity, obesity, stress and—most consistently—excessive consumption of alcohol, but none have been substantiated by science so far.

One hypothesis comes from British biologist Brian J. Ford, who in August 2012 described his experiments with combustion in the magazine New Scientist. According to Ford, a buildup of acetone in the body (which can result from alcoholism, diabetes or a specific kind of diet) can lead to spontaneous combustion.

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