Spontaneous combustion: the act of an object, seemingly for no reason, bursting into flames. A topic previously shrouded in mystery, spontaneous combustion is the bringer of destruction in places ranging from ships to shops, to farms to mills. Once long ago when something catches on fire without any observable cause, it was believed that the devil was involved. Today, it is near flawlessly explained by modern scientific theories.

In order to understand spontaneous combustion, one must know the basics of ordinary combustion. An example of combustion in the form of a chemical equation, is as follows: CH₄ + 2O₂ --> CO₂ + 2H₂O (+ energy) In this example, methane combusts due to it reacting with oxygen gas, forming carbon dioxide gas, and water vapor. Another example of combustion: C₃H₈ + 5O₂ --> 3CO₂ + 4H₂O (+ energy) This examples shows propane reacting with oxygen, forming carbon dioxide, water vapor, and energy.

Something one might notice about both combustion reactions is that there is always a particular substance that contains carbon reacting with oxygen which produces water vapor, carbon dioxide, and amounts of heat and light energy. The substances on both sides of the equation are usually the same for all combustion reactions, however, as with all laws of chemistry, there are some exceptions. Despite the exceptions, it can be stated that in order for an object to combust it should have carbon, and oxygen is required.

The name spontaneous combustion does not correctly describe what is truly going on during a spontaneous combustion. The lie in the name is the word ��spontaneous�. A scientific law says no combustion is ever spontaneous. It was only termed ��spontaneous combustion� because when people observed things igniting without any outside source such as a match or something of that nature, they thought it ignited spontaneously. In truth, scientists eventually discovered that a spontaneous combustion is actually a regular combustion reaction.

A spontaneous combustion actually occurs when there is a pile, stack or some sort of bundled flammable material present. The substance or chemicals in the substance slowly go through reactions with the oxygen in the air such as oxidation, fermentation, or some other type of reaction. Under ordinary conditions, the heat produced by these sorts of reactions with oxygen dissipates into the air, but since the material is bundled, the heat produced cannot escape, and is effectively trapped inside by the bundle. The heat raises the temperature and it does not stop rising, since the heat cannot get out, and in turn the increased temperature increases the rate of the reaction. Eventually, the flammable material becomes so hot that it ignites. (2) Once ago, there were catastrophic explosions aboard coal burning ships. Scientists eventually tied the explosions to spontaneous combustion. Coal is made from the remains of dead creatures. All living things have carbon in them and so therefore, coal has some too. Since ships don�t really have large amounts of spaces to store coal, the coal was stored as piles. The coal would react with the oxygen going through the process of oxidation. However, since they were in piles, the heat created by the reaction couldn�t dissipate, and eventually, the coal would reach a temperature so high that it combusts. When it does combust, large amounts of energy in the forms of heat and light are released. The large amounts of heat were what started the fires. Since most sea journeys took a long time, the coal was guaranteed enough time to react with the oxygen. Soon, crewmembers had to soak the coal in order to stop the coal from combusting. This worked because the water would stop the coal from reaching temperatures high enough for combustion.

A much scarier type of spontaneous combustion is spontaneous combustion of an actual human being. This is a subject of great debate due to the fact many scientists do not believe this is possible, yet many believe it is. No real evidence has been found except for some bodies that seemed to have been burned from inside out. Also, because no one has ever witnessed a real spontaneous human combustion, there are not any definite details to study. To many it is considered as the stuff of urban legends, and is not to be believed. Yet many scientists have devoted their time to studying it.

Like other spontaneous combustion cases, spontaneous human combustion is alleged to be the process of a human body catching on fire due to a massive amount of heat generated by a sort of reaction. In every case of spontaneous human combustion, there were six characteristics distinguishing them from other fires. There was always a sort of ignition source in the room where the body was found. The body is usually reduced to ashes, but sometimes only the torso is burned. About 80% of all the corpses found were female, obese, elderly and alcoholics. Almost no fire damaged is done to anything other than the body. The floor of where the body is found is usually surrounded by a foul smelling yellow liquid. All cases of spontaneous human combustion occur indoors in a small area like a bathroom.

One attempt to explain it was made by Dr. John de Haan. He believed that a human body�s fat content could server as fuel for a fire. He performed an experiment by wrapping a dead pig, who�s fat is very much like a human�s, in a blanket. He then poured a small amount of gasoline over it and ignited it. After a period of about 5 hours, what was left of the pig body looked similar to what some corpses looked like that supposedly went through spontaneous human combustion. The flaw in his theory however, was the time period needed for the body to burn down. In most cases of spontaneous human combustion, people in the adjacent rooms of where the burning person was heard no cries or yells, therefore, leading scientists to believe the combustion was instant. In response to that, it was proposed that when the person starts burning, since they are elderly, shock sets in, and the victim falls unconscious. As they are unconscious, they burn from the inside, fueled by fat. His theory successfully explains the pools of yellow liquid found around the victim�s body. Also, by saying that the human body fat is the fuel for the fires would explain why the majority of the people who died from spontaneous human combustion were overweight, since those types of people have large amounts of fat. What Dr. John de Haan�s theory does not explain however, is what caused the ignition of the body in the first place. And although many tries to figure out the source of combustion have been made, none have been proven. And such is the mystery of the spontaneous combustion of a human being.

Science has made great leaps and bounds over the many years. However, in the case of spontaneous combustion, only the basics and simple parts are understood. The greatest mystery of all types of spontaneous combustion however, has yet to be discovered. How did a human being burst into flames for no reason? Perhaps in the future this great conundrum will finally have an answer.