I stood in my favorite used book store thumbing through a copy of Larry Arnold's exhaustive study of SHC, Ablaze!, priced fairly enough at a four-and-a-half bucks, trying to decide whether or not I wanted to take it home. It's a subject that had always intrigued me. Already I had (and still do) stacks of used books I've bought with the best of intentions, to read whenever I got the time. And this seemed a popular treatment of the subject rather than a critical effort. I passed and purchased other items.
Curiously enough many of the best known cases of SHC involved tobacco smokers. Mary Reeser, who died under strange, fiery circumstances in 1951, is one of the best documented cases of this type. Lots of information about her is available. Here is an old newspaper story about her death. And here is her Findagrave page. Interesting, I think.
The most popular critical theory for explaining these odd cases of people who were nearly completely cremated in environments that suffered minimal heat damage is what has been called the Wick Effect. Under certain situations a person's clothing can, when sufficiently heated, absorb melting body fat and form something similar to a candle wick that can burn at quite high temperatures for long enough so as to cremate the majority of the body.
That sounds reasonable enough to me. Better than, say, the idea that maybe space aliens studying our species and environment periodically aim at their subjects an advanced ray gun capable of doing the deed. Or the idea that maybe God or more likely Satan had something to do with it. I hate those types of suggestions worst of all.
However, I did run across this old item from the October 27, 1829 issue of the Boston Medical And Surgical Journal, under the heading Human Combustion, which gives the best scientific thought of that day:
In a Memoir presented to the Academy of Sciences at Paris, M. Julia de Fontanclle has furnished an account of fifteen cases of spontaneous human combustion, the occurrence of which seems to be supported by respectable testimony. He considers this combustion to depend on a very advanced and putrid degeneration of the system, which suddenly produces very combustible substances, at the expense of the muscular fibre, &c. This degeneration is considered as presenting a perfect analogy with vegetable putrid fermentation and putrefaction. The putrefaction of vegetables is known to occasion the development of so much heat as sometimes to cause their inflammation.
That human combustion does not depend on the combination with atmospheric oxygen, appears probable for three reasons :—1. There is not sufficient heat evolved. 2. There is not the production of a charcoal requiring a high heat for its incineration. 3. There are no ammoniacal products. The effects, therefore, appear to depend on a new arrangement of the elements existing in the body itself.
Although my bedside table is overflowing with books marked according to the progress I've made, I still kind of regret not getting Ablaze! when I had it in my hands.