Pig in a Blanket
In the previous century, arguments had been made against the candle effect and its proposal that the strange fire deaths could be explained as the result of the victim’s clothing acting like the wick of a candle to use the victim’s own body fats to create a powerful, localized fire. It was stated by supporters of the theories of internal combustion and preternatural combustibility that the candle effect would never produce a flame hot enough to break down a body, bones included, and that it would burn slow enough that any reasonably aware person would have plenty of time to stop it. This second argument had already been challenged when it was pointed out that the victims could very well have already been dead when the fires consumed them; and now, with a better understanding of combustion and the human body, the first argument was also challenged.
In 1999, a paper was published by the Forensic Science Society in their journal, Science & Justice, with the imposing title of “Combustion of animal fat and its implications for the consumption of human bodies in fires.” The authors, John DeHaan, S.J. Campbell, and Said Nurbakhsh, had set out to burn small pigs in a variety of situations that could be encountered in fires with the hope that the results would be illustrative of the sorts of damage that could be seen by fire investigators in human bodies under the same conditions... and since the pigs were being used as replacements for human bodies, each was draped over the shoulders with a cotton/polyester blend shirt to replicate clothing that human victims would have been wearing.
What was discovered was that, once ignited, the pigs were capable of continuing to burn with no additional fuel added past their own body fats, as long as they had the charred shirt material to act as a wick. The resulting fires were quite small because of the water content of the flesh was also being burned, so the flames were unlikely to spread to other objects. The flames didn’t burn on their own very long, but it was undeniable that they had been self-sustaining for a short period of time. The results of these initial tests were so intriguing that John DeHaan and Said Nurbakhsh were soon funded to perform a further experiment, specifically to attempt to replicate the body damage found in many of the accounts of the strange fire deaths that had been previously blamed on internal combustion and preternatural combustibility.
The second test was carried out in 1999, and was sponsored by the BBC Television series QED, which filmed the experiment and interviewed DeHaan and Nurbakhsh for an episode devoted to the topic of spontaneous human combustion. For this test, a larger pig carcass was used that better approximated the average size and weight of a human victim, and the whole pig was wrapped in a single-layer cotton blanket to increase the area covered by a possible candle effect. The fire was initially started by a small amount of gasoline, and a carpet under the pig also added to this initial flame, but once these two fuel sources stopped burning the carcass, the body continued to burn for a further four hours on its own, using only its own fat and body tissues as the fuel... and it could have burned longer. The test was ended when it was felt no more useful information was to be gleaned from it.
In that four hour period, the fat from the pig’s body was clearly wicking up on the charred remains of the blanket; and as the burn proceeded, the bones of the thorax and limbs were exposed. It was further discovered that the nature of the flames, which kept fluctuating in temperature, was more efficient at rendering the bones brittle than a single, continuing, hot exposure. Four and a half hours into the test (three hours into the self-sustaining candle effect), the carcass burned into two pieces at the mid-thorax... and all through the burning process, the temperature in the room of the experiment stayed low enough that the experimenters were able to enter and leave as they pleased, and even filmed their interview next to the still burning body.