Spontaneous human combustion

Spontaneous human combustion (SHC) is the pseudoscientific concept of the combustion of a living (or recently deceased) human body without an apparent external source of ignition. In addition to reported cases, descriptions of the alleged phenomenon appear in literature, and both types have been observed to share common characteristics in terms of circumstances and the remains of the victim.
Scientific investigations have attempted to analyze reported instances of SHC and have resulted in hypotheses regarding potential causes and mechanisms, including victim behavior and habits, alcohol consumption and proximity to potential sources of ignition, as well as the behavior of fires that consume melted fats. Natural explanations, as well as unverified natural phenomena, have been proposed to explain reports of SHC. Current scientific consensus is that purported cases of SHC involve overlooked external sources of ignition.
Overview.
"Spontaneous human combustion" refers to the death from a fire originating without an apparent external source of ignition; the fire is believed to start within the body of the victim. This idea and the term "spontaneous human combustion" were both first proposed in 1746 by Paul Rolli in an article published in the "Philosophical Transactions" concerning the mysterious death of Countess Cornelia Zangheri Bandi. Writing in "The British Medical Journal" in 1938, coroner Gavin Thurston describes the phenomenon as having "apparently attracted the attention not only of the medical profession but of the laity one hundred years ago" (referring to a fictional account published in 1834 in the Frederick Marryat cycle). In his 1995 book "Ablaze!", Larry E. Arnold wrote that there had been about 200 cited reports of spontaneous human combustion worldwide over a period of around 300 years.
Characteristics.
The topic received coverage in the "British Medical Journal" in 1938. An article by L. A. Parry cited an 1823-published book "Medical Jurisprudence", which stated that commonalities among recorded cases of spontaneous human combustion included the following characteristics:
"[...]the recorded cases have these things in common:
Alcoholism is a common theme in early SHC literary references, in part because some Victorian era physicians and writers believed spontaneous human combustion was the result of alcoholism.
Scientific investigation.
An extensive two-year research project, involving thirty historical cases of alleged SHC, was conducted in 1984 by science investigator Joe Nickell and forensic analyst John F. Fischer. Their lengthy, two-part report was published in the journal of the International Association of Arson Investigators, as well as part of a book. Nickell has written frequently on the subject, appeared on television documentaries, conducted additional research, and lectured at the New York State Academy of Fire Science at Montour Falls, New York, as a guest instructor.
Nickell and Fischer's investigation, which looked at cases in the 18th, 19th and 20th centuries, showed that the burned bodies were close to plausible sources for the ignition: candles, lamps, fireplaces, and so on. Such sources were often omitted from published accounts of these incidents, presumably to deepen the aura of mystery surrounding an apparently "spontaneous" death. The investigations also found that there was a correlation between alleged SHC deaths and the victim's intoxication (or other forms of incapacitation) which could conceivably have caused them to be careless and unable to respond properly to an accident. Where the destruction of the body was not particularly extensive, a primary source of combustible fuel could plausibly have been the victim's clothing or a covering such as a blanket or comforter.
However, where the destruction was extensive, additional fuel sources were involved, such as chair stuffing, floor coverings, the flooring itself, and the like. The investigators described how such materials helped to retain melted fat, which caused more of the body to be burned and destroyed, yielding still more liquified fat, in a cyclic process known as the "wick effect" or the "candle effect".
According to Nickell and Fischer's investigation, nearby objects often remained undamaged because fire tends to burn upward, but burns laterally with some difficulty. The fires in question are relatively small, achieving considerable destruction by the wick effect, and relatively nearby objects may not be close enough to catch fire themselves (much as one can closely approach a modest campfire without burning). As with other mysteries, Nickell and Fischer cautioned against "single, simplistic explanation for all unusual burning deaths" but rather urged investigating "on an individual basis".
Neurologist Steven Novella has said that skepticism about spontaneous human combustion is now bleeding over into becoming popular skepticism about spontaneous combustion.
A 2002 study by Angi M. Christensen of the University of Tennessee cremated both healthy and osteoporotic samples of human bone and compared the resulting color changes and fragmentation. The study found that osteoporotic bone samples "consistently displayed more discoloration and a greater degree of fragmentation than healthy ones." The same study found that when human tissue is burned, the resulting flame produces a small amount of heat, indicating that fire is unlikely to spread from burning tissue.
Suggested explanations.
While scientific consensus is that incidents which might appear as "spontaneous" combustion did in fact have an external source of ignition—and that the physical possibility of spontaneous human combustion without an external ignition source is extremely implausible—some pseudoscientific hypotheses have been presented which attempt to explain how SHC might occur without an external flame source. Benjamin Radford, science writer and deputy editor of the science magazine "Skeptical Inquirer", casts doubt on the plausibility of spontaneous human combustion: "If SHC is a real phenomenon (and not the result of an elderly or infirm person being too close to a flame source), why doesn't it happen more often? There are 5 billion people in the world [ ⁠today in 1987 ⁠], and yet we don't see reports of people bursting into flame while walking down the street, attending football games, or sipping a coffee at a local Starbucks." Paranormal researcher Brian Dunning states that SHC stories "are simply the rare cases where a natural death in isolation has been followed by a slow combustion from some nearby source of ignition." He further suggested that reports of people suddenly aflame should be called "unsolved deaths by fire", stating that an unknown cause did not necessarily imply that the fire lacked an external ignition source.
Notable examples.
On 2 July 1951, Mary Reeser, a 67-year-old woman, was found burned to death in her house after her landlady realised that the house's doorknob was unusually warm. The landlady notified the police, and upon entering the home they found Reeser's remains completely burned into ash, with only one leg remaining. The chair she was sitting in was also destroyed. Reeser took sleeping pills and was also a smoker. Despite its proliferation in popular culture, the contemporary FBI investigation ruled out the possibility of SHC. A common theory was that she was smoking a cigarette after taking sleeping pills and then fell asleep while still holding the burning cigarette, which could have ignited her gown, ultimately leading to her death. Her daughter-in-law stated, "The cigarette dropped to her lap. Her fat was the fuel that kept her burning. The floor was cement, and the chair was by itself. There was nothing around her to burn".
Margaret Hogan, an 89-year-old widow who lived alone in a house on Prussia Street, Dublin, Ireland, was found burned almost to the point of complete destruction on 28 March 1970. Plastic flowers on a table in the centre of the room had been reduced to liquid and a television with a melted screen sat 12 feet from the armchair in which the ashen remains were found; otherwise, the surroundings were almost untouched. Her two feet, and both legs from below the knees, were undamaged. A small coal fire had been burning in the grate when a neighbour left the house the previous day; however, no connection between this fire and that in which Mrs. Hogan died could be found. An inquest, held on 3 April 1970, recorded death by burning, with the cause of the fire listed as "unknown".
Henry Thomas, a 73-year-old man, was found burned to death in the living room of his council house on the Rassau estate in Ebbw Vale, South Wales, in 1980. His entire body was incinerated, leaving only his skull and a portion of each leg below the knee. The feet and legs were still clothed in socks and trousers. Half of the chair in which he had been sitting was also destroyed. Police forensic officers decided that the incineration of Thomas was due to the wick effect.
In December 2010, the death of Michael Faherty, a 76-year-old man in County Galway, Ireland, was recorded as "spontaneous combustion" by the coroner. The doctor, Ciaran McLoughlin, made this statement at the inquiry into the death: "This fire was thoroughly investigated and I'm left with the conclusion that this fits into the category of spontaneous human combustion, for which there is no adequate explanation."